124 results on '"Seyer, J M"'
Search Results
2. Suppression of murine collagen-induced arthritis by nasal administration of collagen
- Author
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MYERS, L. K., SEYER, J. M., STUART, J. M., and KANG, A. H.
- Published
- 1997
3. Differential expression of two basement membrane collagen genes, COL4A6 and COL4A5, demonstrated by immunofluorescence staining using peptide-specific monoclonal antibodies.
- Author
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Ninomiya, Y, primary, Kagawa, M, additional, Iyama, K, additional, Naito, I, additional, Kishiro, Y, additional, Seyer, J M, additional, Sugimoto, M, additional, Oohashi, T, additional, and Sado, Y, additional
- Published
- 1995
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4. A region in the cytosolic domain of the epidermal growth factor receptor antithetically regulates the stimulatory and inhibitory guanine nucleotide-binding regulatory proteins of adenylyl cyclase.
- Author
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Sun, H, primary, Seyer, J M, additional, and Patel, T B, additional
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- 1995
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5. Processing of TCP pilin by TcpJ typifies a common step intrinsic to a newly recognized pathway of extracellular protein secretion by gram-negative bacteria.
- Author
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Kaufman, M R, primary, Seyer, J M, additional, and Taylor, R K, additional
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- 1991
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6. Fibroblast chemotaxis induction by human recombinant interleukin-4. Identification by synthetic peptide analysis of two chemotactic domains residing in amino acid sequences 70-88 and 89-122.
- Author
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Postlethwaite, A E, primary and Seyer, J M, additional
- Published
- 1991
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7. Increase in the number of atrial natriuretic hormone receptors in regenerating rat liver.
- Author
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Nair, B G, primary, Steinke, L, additional, Yu, Y M, additional, Rashed, H M, additional, Seyer, J M, additional, and Patel, T B, additional
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- 1991
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8. Localization of protective epitopes within the pilin subunit of the Vibrio cholerae toxin-coregulated pilus
- Author
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Sun, D X, primary, Seyer, J M, additional, Kovari, I, additional, Sumrada, R A, additional, and Taylor, R K, additional
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- 1991
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9. Stimulation of fibroblast chemotaxis by human recombinant tumor necrosis factor alpha (TNF-alpha) and a synthetic TNF-alpha 31-68 peptide.
- Author
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Postlethwaite, A E, primary and Seyer, J M, additional
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- 1990
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10. Identification and characterization of a major tolerogenic T-cell epitope of type II collagen that suppresses arthritis in B10.RIII mice.
- Author
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Miyahara, H., Myers, L. K., Rosloniec, E. F., Brand, D. D., Seyer, J. M., Stuart, J. M., and Kang, A. H.
- Subjects
T cells ,EPITOPES ,COLLAGEN ,ARTHRITIS ,DISEASES ,JOINT diseases ,IMMUNOLOGY ,MEDICAL sciences - Abstract
Tolerization of B10.RIII mice (H-2
r ) with intravenously injected type II collagen (CII) renders the animals resistant to induction of collagen-induced arthritis (CIA). In order to clarify 11-2r - restricted T-cell responses that modulate CIA, we have analysed the T-cell proliferative response of B10.RIII mice against cyanogen bromide (CB) peptides of CII, and detected the strongest response to α(II)-CB10 (CII 552–897). A panel of chemically synthesized overlapping peptide homologues was used to deduce the minimum structure of this determinant which was found to be CII 610–618. A 15-residue synthetic peptide flanking this region. CII 607–621, was found to effectively suppress arthritis when administered as a tolerogen. Collectively, these data identify the structural component within α1(II)-CB10 which is capable of inducing tolerance in BIO.RIII mice. A similar approach to the treatment of autoimmune arthritis, involving the institution of self-tolerance, has potential applicability to human rheumatoid arthritis. [ABSTRACT FROM AUTHOR]- Published
- 1995
11. Partial covalent structure of the human alpha 2 type V collagen chain.
- Author
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Myers, J C, Loidl, H R, Stolle, C A, and Seyer, J M
- Abstract
Human cDNA libraries were screened with a cDNA fragment presumably encoding the 3' terminus of a procollagen carboxyl propeptide not identifiable as types I, II, III, or IV by protein sequence or Northern blot hybridization. One clone contained a 1350-base pair insert coding in part for 55 uninterrupted Gly-X-Y triplets. Comparison with the amino acid composition of the COOH-terminal cyanogen bromide (CB) peptides of the alpha 1 and alpha 2 type V collagen chains showed similarity only to the alpha 2(V)CB fragment. To identify the NH2 terminus of the peptide designated by methionine, an additional isolate was sequenced and found to contain a Gly-Met-Pro triplet. Thirty-one amino acids from the NH2 terminus of the alpha 2(V)CB9 fragment were then determined by Edman degradation and found to be identical to those derived from the cDNA clone. The DNA sequence encoding part of the triple helical region establishes for the first time the partial structure of a type V collagen chain. Although comparison of residues 796-1020 of the alpha 2(V) collagenous region with alpha 1 (III), alpha 1(I), and alpha 2(I) shows strong conservation of charged positions, the latter three chains appear considerably more similar to each other than to alpha 2(V). A striking feature of the alpha 2(V) sequence between 918-944 is the absence of proline residues. In the analogous region of alpha 1(I) where this amino acid is also lacking, a flexible site in the rigid triple helical structure of type I collagen has been observed (Hofmann, H., Voss, T., Kuhn, K. and Engel, J. (1984) J. Mol. Biol. 172, 325-343).
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- 1985
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12. Alterations in collagen production in mixed mononuclear leukocyte-fibroblast cultures.
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Hibbs, M S, Postlethwaite, A E, Mainardi, C L, Seyer, J M, and Kang, A H
- Abstract
The cell-cell interactions between fibroblasts and mononuclear leukocytes (MNL) which promote alterations in collagen accumulation were examined using a system of co-culture of human fibroblasts and peripheral blood MNL. The stimulation of collagen production was optimal after 48 h of co-culture and the increase in collagen correlated directly with the number of MNL added. The enhancement of collagen production was seen in both autologous and allogeneic co-cultures. Stimulation of non-collagenous protein was also noted. Co-culture supernatants contained soluble substances that were capable of stimulating collagen production, although they stimulated collagen production to a lesser degree than direct co-culture. Fractionation of these supernatants on Sephadex G-200 revealed a predominant area of stimulatory activity at 160,000 mol wt. Lesser areas of activity were noted at molecular weights of 80,000 and 25,000. Determination of the types of collagen produced by fibroblasts during co-culture with MNL showed that the ratio of type I:III collagen was decreased. These alterations in both the quantitative and qualitative accumulation of collagen mimic the changes often seen in wound healing and early inflammation suggesting that cellular interactions between fibroblasts and MNL may be important in the modulation of collagen production in normal and pathologic states.
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- 1983
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13. Protective immunogenicity and T lymphocyte specificity of a trivalent hybrid peptide containing NH2-terminal sequences of types 5, 6, and 24 M proteins synthesized in tandem.
- Author
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Beachey, E H, Seyer, J M, and Dale, J B
- Abstract
The protective immunogenicity of a hybrid peptide containing tandem copies of types 5, 6, and 24 M protein epitopes was investigated. An NH2-terminal peptide of type 24 M protein was chemically synthesized and then extended to include NH2-terminal peptides of types 6 and 5 M proteins yielding a 34-residue hybrid peptide containing a cysteine residue at its COOH-terminus. When conjugated via the cysteine residue to keyhole limpet hemocyanin (KLH), emulsified in CFA, and injected into rabbits, the synthetic hybrid evoked opsonic antibodies against types 5, 6, and 24 streptococci without stimulating tissue crossreactive immunity. The trivalent hybrid also was capable of priming T lymphocytes in vivo that responded to each of the native serotypes of M protein as well as to the synthetic hybrid peptide in vitro. The primed T cells failed to respond to the individual component peptides contained in the hybrid peptide, suggesting that the hybrid peptide confers conformations resembling the presentations of each of the subpeptides in the respective serotypes of M protein. The brisk immune responses to the type 6 peptide contained in the middle of the tandem hybrid indicates that with judicious placement between proline residues, potentially hidden peptides are readily accessible to the immune system. These results suggest that synthetic tandem peptides can be tailored in a fashion in which each of the component sets of protective epitopes can be made optimally immunoaccessible and immunogenic.
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- 1987
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14. Peptide-specific antibodies identify the alpha 2 chain as the proteoglycan subunit of type IX collagen.
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Konomi, H, Seyer, J M, Ninomiya, Y, and Olsen, B R
- Abstract
Type IX collagen is a recently characterized product of chondrocytes. The molecules of this collagen are heterotrimers of three genetically distinct polypeptide chains. One of the three chains contains chondroitin and/or dermatan sulfate glycosaminoglycan chains, giving the molecule a proteoglycan character. In fact, Type IX collagen has been identified with the proteoglycan Lt (PG-Lt), first isolated by Noro, A., Kimata, K., Oike, Y., Shinomura, T., Maeda, N., Yano, S., Takahashi, N., and Suzuki, S. (1983) J. Biol. Chem. 258, 9323-9331 from chick embryonic tibia and femur. Based on amino acid sequences predicted from the nucleotide sequences of cDNA and genomic clones specific for two of the chains of Type IX collagen, we have synthesized oligopeptides representing portions of the two chains. In addition, an oligopeptide has been made based on a partial amino acid sequence of the third chain. Antibodies against the synthetic peptides have been generated in rabbits, and the polyclonal sera have allowed identification of the three genetically distinct polypeptide subunits of Type IX collagen. In addition, labeling with [35S]sulfate and treatment with chondroitinase ABC demonstrates that glycosaminoglycan chains are present on the subunit that has been given the designation alpha 2(IX).
- Published
- 1986
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15. Transcriptional regulation of type I collagen genes in cultured fibroblasts by a factor isolated from thioacetamide-induced fibrotic rat liver.
- Author
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Raghow, R, Gossage, D, Seyer, J M, and Kang, A H
- Abstract
Recently Hatahara and Seyer (Hatahara, T., and Seyer, J.M. Biochim. Biophys. Acta (1982) 716, 377-382) isolated a factor from fibrotic rat liver which stimulates collagen synthesis in cultured fibroblasts without affecting their rate of proliferation. To investigate the mechanism of fibrogenic factor-mediated enhancement of type I collagen synthesis, we quantitated the levels of mRNAs coding for pro-alpha 1(I) and pro-alpha 2(I) chains in rat dermal fibroblasts. Cell-free translation experiments revealed that the fibrogenic factor caused greater than 5-fold increase in the translatable levels of type I mRNAs. We also quantitated collagen mRNAs by techniques of Northern blotting of glyoxylated poly(A+) RNA followed by hybridization to nick-translated human cDNA clones containing the coding sequence of pro-alpha 1(I) and pro-alpha 2(I) chains. Furthermore, we investigated the relative rates of collagen mRNA transcription in the isolated nuclei of treated and control fibroblasts. Similar quantitation of beta-actin mRNA transcription, which remains unaffected by the treatment with fibrogenic factor, was used as an internal control. We demonstrate that the fibrogenic factor causes a 4-6-fold increase in the rate of transcription of pro-alpha 1(I) and pro-alpha 2(I) genes. Finally, we also show that the rate of intracellular degradation of collagen is not significantly altered in cells treated with fibrogenic factor. These results combined with data on cell-free translation strongly suggest that the increased accumulation of type I collagen mRNA in fibrogenic factor-treated fibroblasts is a consequence of enhanced rates of collagen mRNA transcription.
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- 1984
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16. Biochemical and immunological characterization of the secreted forms of human neutrophil gelatinase.
- Author
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Hibbs, M S, Hasty, K A, Seyer, J M, Kang, A H, and Mainardi, C L
- Abstract
Human neutrophils contain a neutral metalloproteinase which degrades denatured collagens and potentiates the action of interstitial collagenase. This gelatinase is rapidly secreted from neutrophils stimulated with phorbol myristate acetate. The secreted enzyme has been purified by a combination of chromatography on DEAE-cellulose and gelatin-Sepharose. The purified enzyme was latent and had a specific activity of 24,000 units. Estimated molecular weight obtained by gel filtration was 150,000-180,000. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme showed three bands with relative molecular weights of 225,000, 130,000, and 92,000. Electrophoresis in the presence of a reducing agent revealed a single band of Mr = 92,000. All the proteins seen on the unreduced gel were found to contain proteolytic activity against gelatin and native type V collagen. Polyclonal antibodies were prepared against the Mr = 130,000 and 92,000 proteins. When analyzed by immunoblotting, both antibodies recognized all three proteins. Furthermore, the identical three proteins were identified by the antibodies when crude culture medium was immunoblotted. The purified enzyme was inhibited by EDTA and 1,10-phenanthroline but not by serine or thiol proteinase inhibitors, suggesting that the enzyme is a metalloendoproteinase. The enzyme had little or no activity against common protein substrates such as bovine serum albumin or casein. Native type I collagen was not cleaved under conditions where native type V collagen was extensively degraded.
- Published
- 1985
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17. Epitope-specific protective immunogenicity of chemically synthesized 13-, 18-, and 23-residue peptide fragments of streptococcal M protein.
- Author
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Beachey, E H, Tartar, A, Seyer, J M, and Chedid, L
- Abstract
The ability of chemically synthesized subpeptides of type 24 streptococcal M protein to evoke protective antibodies in rabbits was investigated. We synthesized copies of the COOH-terminal 13, 18, and 23 amino acid residues of cyanogen bromide fragment 7 (CB7) of pepsin-extracted type 24 M protein, except that methionine was substituted for homoserine as the COOH-terminal residue. An additional residue of cysteine was added at the COOH terminus of the 13-residue peptide. Each of the peptides, designated S-CB7-(23-35)-Cys, S-CB7-(18-35), and S-CB7-(13-35), when conjugated to lysylated tetanus toxoid with glutaraldehyde, was capable of stimulating formation of protective anti-type 24 M protein antibodies in rabbits. The smallest peptide, S-CB7-(23-35)-Cys, elicited immune responses equally as strong, if not stronger, than those to the longer peptides. A single Lys/Gly substitution in this 13-residue peptide resulted in its failure to stimulate protective antibodies. None of the antisera reacted with heterologous serotypes of M protein and none reacted with frozen sections of human heart tissue. These results indicate that a chemically synthesized peptide fragment corresponding to as few as 13 amino acid residues of streptococcal M protein is capable of evoking protective anti-streptococcal antibodies without evoking antibodies crossreactive with cardiac tissue.
- Published
- 1984
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18. Human alpha 1(III) and alpha 2(V) procollagen genes are located on the long arm of chromosome 2.
- Author
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Emanuel, B S, Cannizzaro, L A, Seyer, J M, and Myers, J C
- Abstract
The multigene procollagen family encodes probably greater than 20 genetically distinct but structurally related polypeptide chains. Recent characterization of human procollagen clones has allowed determination of functional domains within the proteins, genomic organization, and chromosomal location. Previously, we assigned the coordinately expressed type I genes (alpha 1 and alpha 2) to chromosomes 17 and 7, respectively, and now other investigators have mapped the type II gene to chromosome 12 [Strom, C. M., Eddy, R. L. & Shows, T. B. (1984) Somatic Cell Genet. 10, 651-655]. Recently, we isolated cDNA clones encoding the fourth interstitial procollagen, type III, and the alpha 2 chain of the type V cytoskeletal components. To determine whether these genes were clustered with alpha 1(I), alpha 2(I), or alpha 1(II) or were further dispersed in the genome, in situ hybridization of the alpha 1(III) and alpha 2(V) probes to metaphase chromosomes was carried out. Here we report a fourth autosome with procollagen gene loci but the first cytological evidence for linkage. By using normal and translocated cell lines, our results show that both the alpha 1(III) and alpha 2(V) procollagen genes map to the q24.3----q31 region of chromosome 2.
- Published
- 1985
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19. Repeating covalent structure of streptococcal M protein.
- Author
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Beachey, E H, Seyer, J M, and Kang, A H
- Abstract
We have attempted to identify the covalent structure of the M protein molecule of group A streptococci that is responsible for inducing type-specific, protective immunity. M protein was extracted from type 24 streptococci, purified, and cleaved with cyanogen bromide. Seven cyanogen bromide peptides were purified and further characterized. Together, the peptides account for the entire amino acid content of the M protein molecule. Each of the purified peptides possessed the type-specific determinant that inhibits opsonic antibodies for group A streptococci. The primary structures of the amino-terminal regions of each of the purified peptides was studied by automated Edman degradation. The partial sequences of two of the peptides were found to be identical to each other and to that of the uncleaved M protein molecule through at least the first 27 residues. The amino-terminal sequences of the remaining five peptides were identical to each other through the twentieth residue but completely different from the amino-terminal region of the other two peptides. However, the type-specific immunoreactivity and the incomplete analysis of the primary structure of the seven peptides suggest that the antiphagocytic determinant resides in a repeating amino acid sequence in the M protein molecule.
- Published
- 1978
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20. Chemotactic attraction of human fibroblasts to type I, II, and III collagens and collagen-derived peptides.
- Author
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Postlethwaite, A E, Seyer, J M, and Kang, A H
- Abstract
The chemotactice response of human dermal fibroblasts of type I, II, and III human collagens and collagen-derived peptides was quantitated by an in vitro assay. All three native human collagens and constituent alpha chains can serve as chemoattractants for fibroblasts in vitro. When type I, II, and III collagens were digested by bacterial collagenase, the resulting peptides were also chemotactic. In addition, synthetic di- and tripeptides containing hydroxyproline were also chemotactic for fibroblasts. Since collagen is degraded and remodeled at sites of tissue injury and inflammation, these findings suggest that collagen and collagen-degradation peptides might function as chemotactic stimuli for fibroblasts in vivo and attract these cells to effect repair of damaged tissue.
- Published
- 1978
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21. Opsonic antibodies evoked by hybrid peptide copies of types 5 and 24 streptococcal M proteins synthesized in tandem.
- Author
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Beachey, E H, Gras-Masse, H, Tarter, A, Jolivet, M, Audibert, F, Chedid, L, and Seyer, J M
- Abstract
The protective immunogenicity of a hybrid peptide containing tandem copies of types 5 and 24 epitopes was investigated. Carboxy-terminal peptides of the cyanogen bromide-derived fragment 7 (CB7) of type 24 M protein were chemically synthesized, and then extended to include the first 20 residues of the amino-terminus of type 5 M protein. When emulsified in CFA and injected into rabbits without conjugation to a carrier, each of the synthetic hybrid peptides, designated S-M5(1-20)-S-CB7(23-35)C and S-M5(1-20)-S-CB(19-34), evoked opsonic antibodies against both types 5 and 24 streptococci without raising heart tissue-crossreactive immunity. These results suggest that tandem hybrid peptides may provide a new approach to the development of multivalent vaccines, not only to different serotypes of group A streptococci but perhaps also to a variety of other infectious agents.
- Published
- 1986
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22. Biochemical and immunochemical characterization and internal alignment of pepsin-derived collagenous fragments of the alpha 1(IV) chain from bovine kidney cortices.
- Author
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Dixit, S N, Seyer, J M, and Kang, A H
- Abstract
This communication describes the immunochemical and biochemical characterization of three polypeptide chains, alpha 1(IV)130K, alpha 1(IV)110K, and alpha 1(IV)75K belonging to the alpha 1(IV) chain of basement membrane collagen isolated from a pepsin digest of bovine kidney cortices. From the CNBr digests of the mixture of these chain fragments three peptides, a major and two minor peptides with an apparent Mr = 32,000, 24,000 and 13,000, respectively, were purified and characterized. The data presented show that CNBr peptides 24K and 13K are generated from CNBr peptide 32K by pepsin cleavage in the native molecule at the NH2-terminal end. Antisera were raised in rabbits against peptide CB32K. Inhibition assays using enzyme-linked immunoadsorbant assays (ELISA) showed cross-reactivity with alpha 1(IV)130K, alpha 1(IV)110K and alpha 1(IV)75K fragments. Peptides CB24K and 13K also inhibited the antiserum. Antiserum was not active when tested against alpha 1(IV)95K, alpha 1(IV)55K, alpha 2(IV)120K, and alpha 2(IV)95K fragments as inhibitors. These studies provide further evidence that alpha 1(IV)130K, 110K, and 75K are derived from the same parent chain. The pepsin cleavage sites resulting in the formation of these fragments and their internal alignment are described.
- Published
- 1982
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23. Complete primary structure of the human alpha 2 type V procollagen COOH-terminal propeptide.
- Author
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Myers, J C, Loidl, H R, Seyer, J M, and Dion, A S
- Abstract
Recently we presented the partial covalent structure of a type V collagen chain. Analysis of amino acids 796-1020 in the human alpha 2(V) Gly-X-Y region showed strong conservation of charged positions with the interstitial collagens but also revealed substitutions unique to type V. To gain more information about this procollagen and primarily to resolve the ambiguous nature of the 3' noncollagenous propeptide, we sequenced several cDNA clones coding for amino acids adjacent to the carboxyl end of the alpha chain. Here we report the complete primary structure of the alpha 2(V) COOH-terminal propeptide. In general, the latter sequence (270 residues) bears a greater degree of similarity to those of the interstitial rather than the basement membrane procollagens. Compared to the interstitial procollagens, however, more divergence has occurred in alpha 2(V) surrounding the conserved N-asparaginyl-linked carbohydrate attachment site at residues 171-173, and alpha 2(V) possesses an additional potential glycosylation site (Asn-Lys-Thr) located in a hypervariable region near the NH2 terminus. Although certainly premature to form any rigid hypothesis, a pattern emerges that may be characteristic of alpha 2 versus alpha 1 chains. Both the alpha 2(I) and alpha 2(V) telopeptides are devoid of a lysine, which in alpha 1 chains forms an interchain cross-link with residue 87 of the collagenous region. Also in contrast to the interstitial alpha 1 carboxyl propeptides is the absence in alpha 2(I) and alpha 2(V) of a cysteine that probably participates in an interchain disulfide bond. Therefore, one can speculate that those alpha 2 chains, represented only once in procollagen trimers, may not be under the same selective pressure as alpha 1 chains to maintain certain residues responsible for stabilizing the triple helical molecules.
- Published
- 1985
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24. Vimentin-cross-reactive epitope of type 12 streptococcal M protein
- Author
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Kraus, W, Seyer, J M, and Beachey, E H
- Abstract
The NH2-terminal amino acid sequence of type 12 M protein was determined by automated Edman degradation of a 38-kilodalton polypeptide fragment purified from a limited pepsin digest of intact type 12 streptococci. The sequence of the first 13 amino acid residues of the polypeptide confirmed that predicted by the nucleotide sequence of the mature type 12 M protein. A chemically synthesized peptide copying the NH2-terminal 25 residues, SM12(1-25)C, evoked opsonic antibodies against type 12 streptococci as well as renal glomerular cross-reactive antibodies. The serum from one of six rabbits reacted in immunofluorescence tests with human glomeruli in a mesangial staining pattern. The cross-reactive antibodies were completely inhibited by the immunizing peptide and absorption with type 12 streptococci. Subpeptides of the 25-residue synthetic peptide were without inhibitory effect, suggesting that the cross-reactive antibodies are directed against a conformational epitope of SM12(1-25)C. Anti-SM12(1-25)C antisera reacted specifically with the intermediate filament protein vimentin extracted from mesangial cells. None of the cross-reactions of anti-SM12(1-25)C were inhibited by a synthetic peptide SM1(1-26)C of type 1 M protein, which was previously shown to share a cross-reactive epitope with vimentin. These results indicate that type 12 M protein contains at least one vimentin cross-reactive epitope that is clearly distinct from the tetrapeptide epitope shared with vimentin by type 1 M protein.
- Published
- 1989
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25. Post-transcriptional inhibition of collagen and fibronectin synthesis by a synthetic homolog of a portion of the carboxyl-terminal propeptide of human type I collagen.
- Author
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Aycock, R S, Raghow, R, Stricklin, G P, Seyer, J M, and Kang, A H
- Abstract
We evaluated the effects of a synthetic copy of a highly conserved portion (residues 225-246) of the COOH-propeptide of human pro-alpha 2(I) procollagen on collagen, fibronectin, and total protein synthesis by human fibroblasts. Incubation of COOH-propeptide 225-246 with fibroblasts resulted in a concentration-dependent inhibition of both type I procollagen and fibronectin when compared with controls; a 50% inhibition of both fibronectin and type I collagen was observed at a concentration of 45 microM. Since the overall cellular protein synthesis was only minimally affected, COOH-propeptide appeared to specifically inhibit collagen and fibronectin synthesis. The peptide was nontoxic to cells and the inhibition was completely reversible upon removal of the peptide. We measured the steady-state levels of mRNAs coding for procollagen, fibronectin, and beta-actin by hybridization to specific recombinant cDNA probes; there was no significant change in the steady-state level of mRNAs of the three proteins. These results strongly suggest that the biosynthesis of procollagen and fibronectin in COOH-propeptide-treated cells is inhibited at a post-transcriptional level. These data establish a link between collagen and fibronectin synthesis and further define the important interaction of these molecules in the formation of the extracellular matrix.
- Published
- 1986
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26. Type-specific immunogenicity of a chemically synthesized peptide fragment of type 5 streptococcal M protein.
- Author
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Dale, J B, Seyer, J M, and Beachey, E H
- Abstract
We determined the antigenic specificity and protective immunogenicity of two chemically synthesized peptides of type 5 streptococcal M protein. The synthetic peptides, designated S-M5(1-20) and S-M5(20-40), represent the amino-terminal amino acid sequence of the native pepsin-extracted M5 molecule, which is known to contain at least one heart cross-reactive epitope. Initial studies showed that neither of the synthetic peptides was able to bind purified heart-reactive M5 antibodies. In addition, S-M5(1-20), but not S-M5(20-40), contained type-specific antigenic determinants as measured by enzyme-linked immunosorbent inhibition assays. When covalently linked to tetanus toxoid, S-M5(1-20), but not S-M5(20-40), evoked significant levels of type-specific, opsonic (and presumably protective) antibodies in rabbits without evoking heart cross-reactive antibodies.
- Published
- 1983
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27. Identification of an immunosuppressive epitope of type II collagen that confers protection against collagen-induced arthritis.
- Author
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Myers, L K, Stuart, J M, Seyer, J M, and Kang, A H
- Abstract
We have previously reported that collagen-induced arthritis can be suppressed by intravenous injection of native type II (CII) but not type I collagen. We have now identified denatured fragments of CII capable of suppressing collagen-induced arthritis and inducing tolerance. Purified CII was cleaved with cyanogen bromide (CB), and the major resulting peptides were isolated. Female DBA/1 mice were administered OVA, native CII, or one of the CB peptides, intravenously, before immunization with native CII, 6 wk after immunization, mice tolerized with CII and CB11 had a markedly lower incidence of arthritis compared with controls. There was a correlation between the overall antibody response and the incidence of arthritis. In addition, animals tolerized with either CII or CB11 had a decreased antibody response not only to CII, but also to each of the other CB peptides tested. To identify the epitope involved in suppression of arthritis, five synthetic peptides, 21-26 amino acids in length, corresponding to selected regions of CB11, were generated. Each of the peptides was injected intravenously into mice before immunization. Only one of these, CB11 122-147, was capable of suppressing arthritis. In addition, mice given the synthetic peptide CB11 122-147 neonatally were suppressed for arthritis and antibody responsiveness when immunized with CII at 8 wk of age. Thus, we have identified CB11 122-147 as an epitope of CII important in induction of tolerance and suppression of disease. Further experiments narrowing down the pivotal amino acids for the immunogenicity of this epitope and the role this epitope plays in induction and regulation of disease will enhance our understanding of how the immune response to collagen affects autoimmune arthritis.
- Published
- 1989
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28. Cysteine 288: An essential hyperreactive thiol of cytosolic phosphoenolpyruvate carboxykinase (GTP)
- Author
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Lewis, C T, Seyer, J M, and Carlson, G M
- Abstract
Phosphoenolpyruvate carboxykinase from the cytosol of rat liver has 13 cysteines, at least one of which is known to be very reactive and essential for catalytic activity (Carlson, G. M., Colombo, G., and Lardy, H. A. (1978) Biochemistry17, 5329–5338). In order to identify the essential cysteine, this enzyme was modified with the fluorescent sulfhydryl reagent N-(7-dimethylamino-4-methyl-3-coumarinyl)maleimide. Incubation of phosphoenolpyruvate carboxykinase with a 10% molar excess of this maleimide at 0°C results in the rapid and nearly complete loss of catalytic activity. Under these conditions, 1 mol of the maleimide is incorporated per mol inactivated enzyme. The substrate GDP provides almost complete protection against inactivation and modification, while phosphoenolpyruvate protects against the rate, but not the extent, of modification. The pH dependence of the rate of enzyme inactivation suggests that the modified residue has a pKαof approximately 7.0. Purification and sequencing of the labeled peptide identifies the hyperreactive essential cysteine as Cys-288. This cysteine lies between two putative phosphoryl-binding domains and within a hydrophobic sequence.
- Published
- 1989
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29. Repeating covalent structure and protective immunogenicity of native and synthetic polypeptide fragments of type 24 streptococcal M protein. Mapping of protective and nonprotective epitopes with monoclonal antibodies.
- Author
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Beachey, E H, Seyer, J M, Dale, J B, and Hasty, D L
- Abstract
The complete amino acid sequences of three cyanogen bromide peptide fragments (CB3, CB4, and CB50 of type 24 M protein extracted from Streptococcus pyogenes by limited pepsin digestion were determined by automated Edman degradation of the uncleaved peptides and their tryptic peptides. CB3 and CB4 each contain 35 amino acid residues, whereas CB5 contains 37. The sequence of CB3 was found to be: (formula: see text) (where Hse represents homoserine). The sequence of CB4 was identical except for amino acid substitutions of arginine and glutamine at positions 23 and 24, respectively. The sequence of CB5 also was identical with that of CB3 except for substitutions of aspartic acids at positions 28 and 29; leucine, glutamic acid, and glycine at positions 33, 34, and 35, respectively; and an additional two amino acids, alanine and homoserine, at positions 36 and 37, respectively. A comparison of the structures of these three peptide fragments with those previously reported for CB6 and CB7 revealed as few as one to six amino acid substitutions among the five repeating peptides; CB4 and CB6 differed only by a single Asp/Glu substitution at position 26. When covalently linked to polylysine and injected as an emulsion in complete Freund's adjuvant, CB3, CB4, and CB5 each evoked high titers of type-specific opsonic and bactericidal antibodies in rabbits. A chemically synthesized peptide identical with native CB3 except that it contained methionine instead of homoserine at its COOH terminus was similarly immunogenic. None of the conjugated native or synthetic peptides raised antibodies at reacted in immunofluorescence tests with sarcolemmal membranes of human heart tissue. Mapping studies with monoclonal antibodies revealed a number of distinct protective and nonprotective epitopes. The single Asp/Glu substitution between CB4 and CB4 rendered the 35-residue peptide unrecognizable by protective monoclonal antibodies but recognizable by a nonprotective one. Our studies demonstrate that the repeating covalent structures of native and chemically synthesized polypeptide fragments of streptococcal M protein possess several unique as well as repeating epitopes that evoke opsonic and presumably protective, but not heart cross-reactive, antibodies against a rheumatogenic strain of S. pyogenes.
- Published
- 1983
- Full Text
- View/download PDF
30. The sequential limited degradation of bovine myelin basic protein by bovine brain cathepsin D.
- Author
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Whitaker, J N and Seyer, J M
- Published
- 1979
- Full Text
- View/download PDF
31. Stimulation of glycosaminoglycan synthesis in cultured human dermal fibroblasts by interleukin 1. Induction of hyaluronic acid synthesis by natural and recombinant interleukin 1s and synthetic interleukin 1 beta peptide 163-171.
- Author
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Postlethwaite, A E, primary, Smith, G N, additional, Lachman, L B, additional, Endres, R O, additional, Poppleton, H M, additional, Hasty, K A, additional, Seyer, J M, additional, and Kang, A H, additional
- Published
- 1989
- Full Text
- View/download PDF
32. Collagen polymorphism in normal and cirrhotic human liver.
- Author
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Seyer, J M, primary, Hutcheson, E T, additional, and Kang, A H, additional
- Published
- 1977
- Full Text
- View/download PDF
33. Profiles of steady state levels of messenger RNAs coding for type I procollagen, elastin, and fibronectin in hamster lungs undergoing bleomycin-induced interstitial pulmonary fibrosis.
- Author
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Raghow, R, primary, Lurie, S, additional, Seyer, J M, additional, and Kang, A H, additional
- Published
- 1985
- Full Text
- View/download PDF
34. Collagen polymorphism in idiopathic chronic pulmonary fibrosis.
- Author
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Seyer, J M, primary, Hutcheson, E T, additional, and Kang, A H, additional
- Published
- 1976
- Full Text
- View/download PDF
35. Induction of immune tolerance to human type I collagen in patients with systemic sclerosis by oral administration of bovine type I collagen.
- Author
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McKown KM, Carbone LD, Bustillo J, Seyer JM, Kang AH, and Postlethwaite AE
- Subjects
- Administration, Oral, Animals, Cattle, Collagen administration & dosage, Collagen immunology, Down-Regulation, Female, Humans, Immune Tolerance physiology, Interferon-gamma metabolism, Leukocytes, Mononuclear metabolism, Male, Middle Aged, Patient Compliance, Scleroderma, Systemic immunology
- Abstract
Objective: To determine whether oral tolerance to type I collagen (CI) could be induced in patients with systemic sclerosis (SSc)., Methods: Twenty adult patients with limited or diffuse SSc were enrolled in a study to receive 0.1 mg of solubilized native bovine CI daily for 1 month, followed by 0.5 mg daily for 11 months. Peripheral blood mononuclear cells (PBMC) were obtained from the patients and cultured with human alpha1(I) and alpha2(I) chains, before and after CI treatment. Culture supernatants were analyzed for levels of interferon-gamma (IFNgamma) and interleukin-10 (IL-10). Sera obtained before and after treatment were analyzed for levels of soluble IL-2 receptor (sIL-2R). Although this study was not intended to assess the clinical efficacy of oral CI administration in SSc, selected measures of disease severity and organ involvement were evaluated., Results: Oral administration of CI to SSc patients induced significant reductions in levels of IFNgamma and IL-10 in alpha1(I)- and alpha2(I)-stimulated PBMC culture supernatants, indicating that T cell immunity to CI was decreased by this treatment. Serum levels of sIL-2R also decreased significantly after oral CI treatment, suggesting a reduction in T cell activation. Significant improvements occurred in the modified Rodnan skin thickness score and the modified Health Assessment Questionnaire after 12 months of oral CI in this open trial. The lung carbon monoxide diffusing capacity improved statistically and showed a trend toward clinically significant improvement., Conclusion: Oral administration of bovine CI to patients with diffuse or limited SSc induces a reduction in T cell reactivity to human CI, appears to be well tolerated, and does not worsen the disease. Further evaluation of oral tolerance to CI in patients with SSc is justified to determine whether it has therapeutic efficacy.
- Published
- 2000
- Full Text
- View/download PDF
36. Lack of efficacy of oral bovine type II collagen added to existing therapy in rheumatoid arthritis.
- Author
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McKown KM, Carbone LD, Kaplan SB, Aelion JA, Lohr KM, Cremer MA, Bustillo J, Gonzalez M, Kaeley G, Steere EL, Somes GW, Myers LK, Seyer JM, Kang AH, and Postlethwaite AE
- Subjects
- Administration, Oral, Adolescent, Adult, Aged, Animals, Arthritis, Rheumatoid pathology, Cattle, Collagen administration & dosage, Double-Blind Method, Drug Therapy, Combination, Female, Humans, Joints drug effects, Joints pathology, Male, Middle Aged, Pain Measurement, Severity of Illness Index, Surveys and Questionnaires, Treatment Outcome, Antirheumatic Agents therapeutic use, Arthritis, Rheumatoid drug therapy, Collagen therapeutic use
- Abstract
Objective: To investigate the efficacy of oral type II collagen (CII) in the treatment of rheumatoid arthritis (RA), when added to existing therapy., Methods: Patients with active RA (n = 190) were randomized into a 6-month, double-blind, placebo-controlled trial. Patients continued to take their current arthritis medications. Patients received either placebo or bovine CII, 0.1 mg/day for 1 month, then 0.5 mg/day for 5 months., Results: There were no significant differences between the baseline characteristics of either group. The primary response parameter was the American College of Rheumatology (ACR) preliminary definition of improvement in RA (ACR 20). There was no statistically significant difference in the ACR 20 after 6 months (20.0% of placebo patients; 16.84% of bovine CII patients). There were significant differences in several clinical variables after treatment, all favoring the placebo group., Conclusion: Oral solubilized bovine CII, added to existing therapy, did not improve disease activity in patients with RA.
- Published
- 1999
- Full Text
- View/download PDF
37. Intracellular phosphorylation of the Sendai virus P protein.
- Author
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Byrappa S, Hendricks DD, Pan YB, Seyer JM, and Gupta KC
- Subjects
- Animals, COS Cells, Cell-Free System, Phosphorylation, Virus Replication, Phosphoproteins physiology, Sendai virus physiology, Viral Proteins physiology
- Abstract
Phosphorylation status of the Sendai virus P protein was examined during virus infection and compared with cell-free phosphorylation. P protein from Sendai virus-infected (VI) and P/C gene-transfected (PT) mammalian cells and from purified virions (PV) was phosphorylated at only serine residues. In contrast, cell-free phosphorylation of the P protein with virion-associated protein kinase (VAPK) occurred at both threonine and serine. Tryptic phosphopeptide maps of the P protein from VI, PT, and PV showed that the phosphorylation was primarily localized on one peptide (TP1), while VAPK phosphorylated the P protein on several peptides. There was no change in the steady-state phosphopeptide map of the P protein during virus replication, indicating that the TP1 is constitutively phosphorylated. Inhibition of cellular phosphatases (PP1 and PP2A) by okadaic acid (OA) in virus-infected cells caused a sixfold increase in the P protein phosphorylation, solely at serine residues. The phosphopeptide map of the OA-P protein revealed that phosphorylation occurred on several peptides, but the OA-P map was significantly different from the VAPK-P map. However, additional phosphorylation of the P protein did not block its association with nucleocapsids. These results suggest that the Sendai virus P protein is constitutively phosphorylated primarily at one locus but has the potential for phosphorylation at additional sites. Further, our results do not show any correlations between the intracellular and cell-free phosphorylation of the P protein and, therefore, question the validity of cell-free phosphorylations.
- Published
- 1995
- Full Text
- View/download PDF
38. Collagen-induced arthritis in B10.RIII mice (H-2r): identification of an arthritogenic T-cell determinant.
- Author
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Myers LK, Miyahara H, Terato K, Seyer JM, Stuart JM, and Kang AH
- Subjects
- Amino Acid Sequence, Animals, Cattle, Chickens, Collagen chemistry, Mice, Mice, Inbred Strains, Molecular Sequence Data, Peptide Fragments immunology, Arthritis immunology, Autoimmune Diseases immunology, Collagen immunology, Epitopes immunology, T-Lymphocytes immunology
- Abstract
Susceptibility to collagen-induced arthritis (CIA), a murine model of autoimmune arthritis, is strongly linked to only two major histocompatibility complex (MHC) haplotypes, H-2q and H-2r. In order to identify the determinants of type II collagen (CII) required to induce arthritis in H-2r-bearing mice, B10.RIII mice were immunized with bovine, chick or human CII. Only bovine CII induced significant arthritis and autoantibodies. When the major CNBr peptides of bovine collagen were isolated and used for immunization, only mice immunized with CB8, representing CII 403-551, developed arthritis. To identify immunogenic epitope(s) within CB8, a panel of synthetic peptides representing overlapping sequences of the bovine peptide was generated. When each peptide was cultured with T cells from B10.RIII mice immunized with CII, one peptide, representing CII 430-466, contained a major T-cell epitope. By using an in vitro lymphokine production assay, the T-cell epitope was further narrowed to CII 442-456. These findings suggest that a T-cell determinant important for the initiation of arthritis in B10.RIII (H-2r) mice is located within a 15 amino acid sequence, residues 442-456 of bovine CII.
- Published
- 1995
39. A pentapeptide from type I procollagen promotes extracellular matrix production.
- Author
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Katayama K, Armendariz-Borunda J, Raghow R, Kang AH, and Seyer JM
- Subjects
- Amino Acid Sequence, Animals, Cell Line, Cells, Cultured, Chick Embryo, Extracellular Matrix drug effects, Humans, Kinetics, Molecular Sequence Data, Transforming Growth Factor beta pharmacology, Extracellular Matrix physiology, Fibronectins biosynthesis, Peptide Fragments pharmacology, Procollagen biosynthesis, Procollagen pharmacology
- Abstract
The NH2 and COOH propieces of fibril-forming collagens are cleaved off extracellularly and have been implicated in feedback regulation of their own synthesis. Recently, we showed that a subfragment of the carboxyl-terminal propeptide of type I collagen (residues 197-241) dramatically augments extracellular matrix production in subconfluent fibroblasts. This stimulation of type I collagen, type III collagen, and fibronectin production occurred in a dose- and time-dependent manner with no effect on total protein synthesis or on the ratio of secreted proteins to cell-associated proteins (Katayama, K., Seyer, J.M., Raghow, R., and Kang, A.H. (1991) Biochemistry 30, 7097-7104). In the present report, we have extensively dissected this subfragment of the propeptide and found that the pentapeptide Lys-Thr-Thr-Lys-Ser (residues 212-216) is the minimum sequence necessary for potent stimulation of collagen and fibronectin production in a variety of mesenchymal cells. We postulate that the extracellular matrix production in fibroblasts may be subject to either positive or negative feedback regulation depending on the repertoire of specific proteases during postinflammatory tissue regeneration and fibrosis.
- Published
- 1993
40. Identification of vicinal thiols of phosphoenolpyruvate carboxykinase (GTP).
- Author
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Lewis CT, Seyer JM, Cassell RG, and Carlson GM
- Subjects
- Alkylation, Amino Acid Sequence, Animals, Azides pharmacology, Chromatography, High Pressure Liquid, Cysteine analysis, Cysteine chemistry, Cystine analysis, Cystine chemistry, Cytosol enzymology, Disulfides chemistry, Dithionitrobenzoic Acid pharmacology, Guanosine Triphosphate analogs & derivatives, Guanosine Triphosphate pharmacology, Iodoacetates, Iodoacetic Acid, Molecular Sequence Data, Peptide Fragments chemistry, Peptide Fragments isolation & purification, Phosphoenolpyruvate Carboxykinase (GTP) chemistry, Phosphoenolpyruvate Carboxykinase (GTP) radiation effects, Rats, Trypsin metabolism, Liver enzymology, Phosphoenolpyruvate Carboxykinase (GTP) analysis, Sulfhydryl Compounds analysis
- Abstract
Phosphoenolpyruvate carboxykinase (PEPCK) from the cytosol of rat liver has 13 cysteines, at least one of which (Cys288) is known to be very reactive and critical for catalytic activity (Lewis, C. T., Seyer, J. M., and Carlson, G. M. (1989) J. Biol. Chem. 264, 27-33). Previous results provided evidence for the existence of at least 1 pair of vicinal cysteines within or near the active site of PEPCK (Lewis, C. T., Haley, B. E., and Carlson, G. M. (1989) Biochemistry 28, 9248-9255). An intramolecular cystine disulfide is induced to form upon treatment of PEPCK with equimolar 5,5'-dithiobis(2-nitrobenzoate) (Nbs2) or upon irradiation of the enzyme in the presence of the photoaffinity probe 8-azidoGTP. In each case, modification is accompanied by a substantial loss in catalytic activity, and substrates protect against inactivation and modification. We now report the identification of these modified thiols by differential alkylation of cysteines and half-cystines with radioactive iodoacetate, followed by isolation and sequencing of the modified tryptic peptides. The results indicate that the disulfide formed by equimolar Nbs2 lies within a 15-residue region of the PEPCK sequence that includes Cys399, Cys407, and Cys413. In addition, Cys407 and/or Cys413 also appear to participate in formation of the disulfide induced by 8-azidoGTP. These thiols lie very near a consensus sequence that has been suggested to represent the binding site for the guanine ring of GTP.
- Published
- 1993
41. Transcriptional mechanisms of type I collagen gene expression are differentially regulated by interleukin-1 beta, tumor necrosis factor alpha, and transforming growth factor beta in Ito cells.
- Author
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Armendariz-Borunda J, Katayama K, and Seyer JM
- Subjects
- Animals, Blotting, Northern, Cell Nucleus drug effects, Cell Nucleus physiology, Cells, Cultured, Collagen biosynthesis, Extracellular Matrix drug effects, Extracellular Matrix physiology, Liver cytology, Liver drug effects, Poly A genetics, Poly A isolation & purification, Proline metabolism, RNA, Messenger genetics, RNA, Messenger isolation & purification, RNA, Messenger metabolism, Rats, Rats, Inbred Strains, Collagen genetics, Gene Expression Regulation drug effects, Interleukin-1 pharmacology, Liver physiology, Transcription, Genetic drug effects, Transforming Growth Factor beta pharmacology, Tumor Necrosis Factor-alpha pharmacology
- Abstract
Regulation of the procollagen type I (Pro alpha 1) gene in cultured Ito cells by diverse cytokines was studied. Specifically, we have examined the effect of interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF alpha), and transforming growth factor beta (TGF beta) on collagen biosynthesis, levels of Pro alpha 1 (I) mRNA, and rate of transcription of Pro alpha 1 (I) gene. TGF beta stimulated procollagen synthesis at least 2-fold at every concentration tested (5-20 ng/ml), whereas TNF alpha inhibited it at the same concentrations. In contrast to what occurs in dermal fibroblasts, IL-1 beta (5-20 units/ml) preferentially inhibited procollagen production as measured by [3H]proline incorporation. A similar pattern was obtained when total protein synthesis was analyzed by [25S]methionine radiolabeling. Interestingly, while TGF beta-treated cells exhibited greater than 3-fold increase in steady-state levels of Pro alpha 1 (I) mRNA, the treatment with IL-1 had no effect on procollagen mRNA levels. TNF alpha treatment resulted in a 2-fold decrease in the amount of collagen mRNA. The treatment with combinations of cytokines indicated that collagen gene expression in Ito cells is differentially regulated by these cytokines. Furthermore, nuclear run-off transcription experiments were performed. The results obtained suggest that TGF beta regulates increasing collagen type I gene expression at transcriptional levels, and TNF alpha inhibits the transcriptional rate of Pro alpha 1 (I) gene. It is noteworthy that IL-1 beta acts on collagen type I gene regulation by a separate mechanism at a posttranscriptional level.
- Published
- 1992
42. Further characterization of the loop structure of platelet glycoprotein IIIa: partial mapping of functionally significant glycoprotein IIIa epitopes.
- Author
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Kouns WC, Newman PJ, Puckett KJ, Miller AA, Wall CD, Fox CF, Seyer JM, and Jennings LK
- Subjects
- Amino Acid Sequence, Antibodies, Monoclonal, Blood Platelets chemistry, Blotting, Western, Chymotrypsin metabolism, Epitopes chemistry, Flow Cytometry, Humans, Immunoblotting, Kinetics, Molecular Sequence Data, Molecular Weight, Peptide Fragments chemistry, Peptide Fragments metabolism, Peptide Mapping, Platelet Membrane Glycoproteins immunology, Platelet Membrane Glycoproteins metabolism, Protein Conformation, Platelet Membrane Glycoproteins chemistry
- Abstract
Glycoprotein (GP) IIb-IIIa serves as the platelet fibrinogen receptor. Studies of the tertiary structure of GPIIIa have shown that the protein has a large loop structure of at least 325 amino acids in length. To further characterize this loop structure, intact platelets were digested with alpha-chymotrypsin. Digestion products were examined using the anti-GPIIIa monoclonal antibodies (MoAbs) AP3, D3GP3, and C5GP3, as well as the human alloantibody, anti-PLA1. AP3 recognized GPIIIa digestion products of 109, 95, and 68 Kd. D3GP3 and C5GP3 recognized an additional band of 51 Kd. Time course digestions demonstrated that the 51-Kd fragment was generated by proteolysis of the 68-Kd peptide. Sequence analysis of the reduced 51-Kd peptide showed that this fragment began at amino acid 422. The nonreduced 51-Kd peptide was reactive with antibodies directed against the first 13 amino acids of GPIIIa, demonstrating the presence of a covalently attached N-terminal peptide. These data suggest that: (1) the minimum length of the loop structure is at least 384 amino acids; (2) the AP3 epitope is formed at least in part by a determinant contained within residues 348 to 421; and (3) the D3GP3 and C5GP3 epitopes are contained within amino acids 422 to 692 of GPIIIa, a region that may be flexible and involved in conformational changes that occur after ligand binding.
- Published
- 1991
43. cDNA cloning and expression of platelet p24/CD9. Evidence for a new family of multiple membrane-spanning proteins.
- Author
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Lanza F, Wolf D, Fox CF, Kieffer N, Seyer JM, Fried VA, Coughlin SR, Phillips DR, and Jennings LK
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Cricetinae, Cricetulus, Electrophoresis, Polyacrylamide Gel, Female, Gene Expression Regulation, Humans, Molecular Sequence Data, Open Reading Frames, Polymerase Chain Reaction, Precipitin Tests, Restriction Mapping, Sequence Alignment, Tetraspanin 29, Transcription, Genetic, Xenopus, Antigens, CD genetics, Antigens, Differentiation genetics, Blood Platelets metabolism, DNA genetics, Membrane Glycoproteins
- Abstract
This study was designed to clone, sequence, and express the full-length cDNA for the human platelet p24/CD9 antigen. A 1.3-kilobase cDNA clone was identified that has an open reading frame encoding a mature protein of 228 amino acids (approximately 25,400 Da) containing 10 cysteine residues and four putative transmembrane domains. The identity of the clone was confirmed by: (i) its predicted size, (ii) identity to four peptide sequences from the isolated protein including the NH2 terminus, and (iii) expression of the isolated clone in Xenopus oocytes and Chinese hamster ovary cells. p24/CD9 has sequence identity (24-34%) to four other cell-surface proteins: ME491, a melanoma antigen; CO-029, a carcinoma antigen; CD37, a leukocyte antigen; and SM23, an antigen of the parasitic helminth Schistosoma mansoni. The five proteins have a similar number of amino acids and are characterized by the presence of four putative transmembrane domains. These data indicate the presence of a new family of surface antigens that may function in cellular activation and differentiation.
- Published
- 1991
44. Genomic organization of the human procollagen alpha 1(II) collagen gene.
- Author
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Huang MC, Seyer JM, Thompson JP, Spinella DG, Cheah KS, and Kang AH
- Subjects
- Base Sequence, Cloning, Molecular, Collagen genetics, Exons, Genetic Vectors, Humans, Introns, Molecular Sequence Data, Plasmids, Restriction Mapping, Genes, Procollagen genetics
- Abstract
The nucleotide sequence of the human procollagen alpha 1(II) collagen gene extending from within the first intron through exon 15, and part of the 15th intron has been determined. This sequence analysis (7056 bases) identifies the intron/exon organization of the region of this gene encoding the N-propeptide and part of the triple-helical domain. Structural comparison of this with the genes of other human fibrillar collagens shows considerable diversity in terms of size and number of introns and exons that encodes the N-propeptide domain. Although the genomic structure of the human procollagen alpha 1(II) gene is quite different from the rat procollagen alpha 1(II) gene, the nucleotide coding sequences are 89% identical.
- Published
- 1991
- Full Text
- View/download PDF
45. The amino-terminal 29- and 72-Kd fragments of fibronectin mediate selective monocyte recruitment.
- Author
-
Lohr KM, Kurth CA, Xie DL, Seyer JM, and Homandberg GA
- Subjects
- Chemotaxis drug effects, Chemotaxis physiology, Enzyme-Linked Immunosorbent Assay, Fibronectins analysis, Fibronectins isolation & purification, Humans, Monocytes physiology, Peptide Fragments analysis, Peptide Fragments isolation & purification, Fibronectins physiology, Monocytes drug effects, Peptide Fragments physiology
- Abstract
Proteolytic fragments of fibronectin (Fn) can possess properties not inherent to intact Fn. Previously, only mixtures of low molecular weight Fn fragments, and the 120-Kd fibroblastic cell-binding segment, but not intact Fn, were shown to be selectively chemotactic for human monocytes (MOs). In order to determine if other structural domains of Fn were responsible, we tested six Fn fragments. The amino-terminal 72-Kd fragment at 1.5 microns was about 75% as potent as zymosan-activated serum (ZAS). Its amino-terminal 29-Kd degradation product at 1.0 micron was about one third as potent as ZAS. Checkerboard analysis confirmed chemotaxis. Complexing gelatin to 72-Kd fragments reduced MO chemotaxis by 28% to 30%. Reducing disulfide bonds in 29- and 72-Kd segments had no effect. A synthetic peptide containing the thrombin cleavage site between the 29- and 50-Kd segments of the 72-Kd fragment was chemotactic. The 50-, 190/170-, 35-, and 160/150/120-Kd fragments, and intact Fn were not chemotactic for MOs. The data suggest that the 72-Kd fragment and its 29-Kd subfragment are additional Fn fragments that mediate selective MO chemotaxis. We speculate that proteinases present at inflammatory sites can liberate such fragments that selectively recruit MOs.
- Published
- 1990
46. Modulation of fibroblast functions by interleukin 1: increased steady-state accumulation of type I procollagen messenger RNAs and stimulation of other functions but not chemotaxis by human recombinant interleukin 1 alpha and beta.
- Author
-
Postlethwaite AE, Raghow R, Stricklin GP, Poppleton H, Seyer JM, and Kang AH
- Subjects
- Cell Division drug effects, Chemotaxis drug effects, Collagen metabolism, Dinoprostone, Gene Expression Regulation drug effects, Humans, Metalloendopeptidases antagonists & inhibitors, Microbial Collagenase biosynthesis, Prostaglandins E biosynthesis, Protease Inhibitors biosynthesis, RNA, Messenger genetics, Recombinant Proteins pharmacology, Interleukin-1 pharmacology, Procollagen genetics
- Abstract
Interleukin-1 (IL-1) is synthesized by and released from macrophages in response to a variety of stimuli and appears to play an essential role in virtually all inflammatory conditions. In tissues of mesenchymal origin (e.g., cartilage, muscle, bone, and soft connective tissue) IL-1 induces changes characteristic of both destructive as well as reparative phenomena. Previous studies with natural IL-1 of varying degrees of purity have suggested that it is capable of modulating a number of biological activities of fibroblasts. We have compared the effects of purified human recombinant (hr) IL-1 alpha and beta on several fibroblast functions. The parameters studied include cell proliferation, chemotaxis, and production of collagen, collagenase, tissue inhibitor of metalloproteinase (TIMP), and prostaglandin (PG) E2. We observed that hrIL-1s stimulate the synthesis and accumulation of type I procollagen chains. Intracellular degradation of collagen is not altered by the hrIL-1s. Both IL-1s were observed to increase the steady-state levels of pro alpha 1(I) and pro alpha 2(I) mRNAs, indicating that they exert control of type I procollagen gene expression at the pretranslational level. We found that both hrIL-1 alpha and beta stimulate synthesis of TIMP, collagenase, PGE2, and growth of fibroblasts in vitro but are not chemotactic for fibroblasts. Although hrIl-1 alpha and beta both are able to stimulate production of PGE2 by fibroblasts, inhibition of prostaglandin synthesis by indomethacin has no measurable effect on the ability of the IL-1s to stimulate cell growth or production of collagen and collagenase. Each of the IL-1s stimulated proliferation and collagen production by fibroblasts to a similar degree, however hrIL-1 beta was found to be less potent than hrIL-1 alpha in stimulating PGE2 production. These observations support the notion that IL-1 alpha and beta may both modulate the degradation of collagen at sites of tissue injury by virtue of their ability to stimulate collagenase and PGE2 production by fibroblasts. Furthermore, IL-1 alpha and beta might also direct reparative functions of fibroblasts by stimulating their proliferation and synthesis of collagen and TIMP.
- Published
- 1988
- Full Text
- View/download PDF
47. Investigation of type I and type III collagens of the lung in progressive systemic sclerosis.
- Author
-
Seyer JM, Kang AH, and Rodnan G
- Subjects
- Adult, Collagen genetics, Collagen isolation & purification, Cyanogen Bromide, Female, Humans, Male, Middle Aged, Polymorphism, Genetic, Collagen analysis, Lung analysis, Scleroderma, Systemic metabolism
- Abstract
The interstitial collagens, type I and type III, were investigated in lung tissue from patients with progressive systemic sclerosis (PSS) with pulmonary involvement. By use of CNBr digestion of whole tissue, the relative content of type I versus type III collagen was unchanged. This contrasts with idiopathic pulmonary fibrosis. Limited pepsin digestion released greater amounts of collagen (55%) than normal (16%), but the individual collagen chains were chemically indistinguishable. A reduced amount of the more stable collagen crosslink, hydroxylysinonorleucine, was observed which was consistent with the relatively greater degree of solubilization.
- Published
- 1981
- Full Text
- View/download PDF
48. Primary structure of protective antigens of type 24 streptococcal M protein.
- Author
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Beachey EH, Seyer JM, and Kang AH
- Subjects
- Amino Acid Sequence, Amino Acids analysis, Antibodies, Bacterial biosynthesis, Bacterial Proteins immunology, Cyanogen Bromide metabolism, Epitopes, Immunodiffusion, Peptides analysis, Peptides immunology, Streptococcus pyogenes immunology, Trypsin metabolism, Antigens, Bacterial analysis, Bacterial Proteins analysis, Streptococcus pyogenes analysis
- Published
- 1980
49. Type-specific protective immunity evoked by synthetic peptide of Streptococcus pyogenes M protein.
- Author
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Beachey EH, Seyer JM, Dale JB, Simpson WA, and Kang AH
- Subjects
- Amino Acid Sequence, Animals, Antibody Formation, Epitopes, Immunity, Cellular, Mice, Oligopeptides chemical synthesis, Oligopeptides immunology, Rabbits, Vaccines, Antigens, Bacterial, Bacterial Outer Membrane Proteins, Bacterial Proteins immunology, Carrier Proteins
- Published
- 1981
- Full Text
- View/download PDF
50. Covalent structure of collagen: amino-acid sequence of chymotryptic peptides from the carboxyl-terminal region of alpha2-CB3 of chick-skin collagen.
- Author
-
Dixit SN, Seyer JM, and Kang AH
- Subjects
- Amino Acid Sequence, Amino Acids analysis, Animals, Chickens, Chymotrypsin, Maleates, Peptide Fragments analysis, Skin, Thermolysin, Trypsin, Collagen
- Abstract
The amino acid sequence of chymotryptic peptides C4 and C5 which together make up 206 COOH-terminal residues of alpha2-CB3 of chick skin collagen is described. This in combination with the sequence of 132 residues from the amino-terminal region published earlier [Dixit, Seyer, and Kang (1977) Eur. J. Biochem. 73, 213-221] completes the total amino acid sequence of the large CNBr peptide, alpha2-CB3 of chick skin collagen. The amino acid sequence was determined by automated Edman degradation of intact peptides C4 and C5 and their respective tryptic and maleylated tryptic peptides, and thermolytic peptides of C4. The comparison of the sequence with the homologous segment of alpha1(I) chain showed striking variance of over 51% within the same species.
- Published
- 1977
- Full Text
- View/download PDF
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