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2. Cycloviolins A-D, anti-HIV macrocyclic peptides from Leonia cymosa

Author

Hallock, Yali F., Sowder, Raymond C.,II, Pannell, Lewis K., Hughes, Courtney B., Johnson, Donald G., Gulakowski, Robert, Cardellina, John H.,II, and Boyd, Michael R.

Subjects
Chemistry, Organic -- Research, Peptides -- Research, Amino acids -- Research, HIV infection -- Prevention, Biological sciences, Chemistry
Abstract

Research has been conducted on the isolation of anti-HIV macrocyclic peptides cycloviolins A-D. Determination of their amino acid composition via MALDI-TOF and FAB MS is described.

Published
2000

3. Probing the topography of HIV-1 nucleocapsid protein with the alkylating agent N-ethylmaleimide

Author

Chertova, Elena N., Kane, Bradley P., McGrath, Connor, Johnson, Donald G., Sowder, Raymond C., II, Arthur, Larry O., and Henderson, Louis E.

Subjects
Retroviruses -- Research, Proteins -- Analysis, HIV (Viruses) -- Research, Alkylating agents -- Research, Peptides -- Research, Zinc compounds -- Research, Biological sciences, Chemistry
Abstract

The reactivity of specific Cys residues in the retroviral nucleocapsid protein was investigated by analyzing the topography of zinc fingers in different contexts using chemical probes. Experimental results showed that the conformation of free NCp7 inhibits the initial site of attack to Cys-49 and that the reactivity of thiols in full-length protein is different from that of the isolated zinc finger peptides. These results provide relevant parameters for the rational development of drugs for retroviral zinc fingers.

Published
1998

4. Complex interactions of HIV-1 nucleocapsid protein with oligonucleotides

Author

Fisher, Robert J., Fivash, Matthew J., Stephen, Andrew G., Hagan, Nathan A., Shenoy, Shilpa R., Medaglia, Maxine V., Smith, Lindsey R., Worthy, Karen M., Simpson, John T., Shoemaker, Robert, McNitt, Karen L., Johnson, Donald G., Hixson, Catherine V., Gorelick, Robert J., Fabris, Daniele, Henderson, Louis E., and Rein, Alan

Published
2006

21. Isolation and characterization of adociavirin, a novel HIV-inhibitory protein from the spongeAdociasp.1

Author

O'Keefe, Barry R, primary, Erim, Tolga, additional, Beutler, John A, additional, Cardellina, John H, additional, Gulakowski, Robert J, additional, Krepps, Benjamin L, additional, McMahon, James B, additional, Sowder, Raymond C, additional, Johnson, Donald G, additional, Buckheit, Robert W, additional, Halliday, Susan, additional, and Boyd, Michael R, additional

Published
1998
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22. Ubiquitin Is Covalently Attached to the p6 Gag Proteins of Human Immunodeficiency Virus Type 1 and Simian Immunodeficiency Virus and to the p12 Gag Protein of Moloney Murine Leukemia Virus

Author

Ott, David E., primary, Coren, Lori V., additional, Copeland, Terry D., additional, Kane, Bradley P., additional, Johnson, Donald G., additional, Sowder, Raymond C., additional, Yoshinaka, Yoshiyuki, additional, Oroszlan, Stephen, additional, Arthur, Larry O., additional, and Henderson, Louis E., additional

Published
1998
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31. Isolation and characterization of adociavirin, a novel HIV-inhibitory protein from the sponge Adocia sp.1Part 51 in the series 'Anti-HIV Natural Products'; for part 50, see Fuller, R.W., Westergaard, C.K., Collins, J.W., Cardellina, J.H. II and Boyd, M.R. (1998) J. Nat. Prod. (submitted).1

Author

O'Keefe, Barry R, Erim, Tolga, Beutler, John A, Cardellina, John H, Gulakowski, Robert J, Krepps, Benjamin L, McMahon, James B, Sowder, Raymond C, Johnson, Donald G, Buckheit, Robert W, Halliday, Susan, and Boyd, Michael R

Subjects
gp120, Human immunodeficiency virus, Macrophage, Sponge protein, Anti-HIV protein
Abstract

Aqueous extracts of the New Zealand sponge Adocia sp. (Haplosclerida) displayed potent anticytopathic activity in CEM-SS cells infected with HIV-1. Protein fractions of the extract bound both to the viral coat protein gp120 and to the cellular receptor CD4, but not to other tested proteins. The purified active protein, named adociavirin, was characterized by isoelectric focusing, amino acid analysis, MALDI-TOF mass spectrometry and N-terminal sequencing. Adociavirin, a disulfide-linked homodimer with a native molecular weight of 37 kDa, was active against diverse strains and isolates of HIV-1, as well as HIV-2, with EC50 values ranging from 0.4 nM to >400 nM. The anti-HIV potency of adociavirin appears dependent on host cell type, with macrophage cultures being the most sensitive and peripheral blood lymphocytes the most resistant.

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32. Mutational Analysis of the Hydrophobic Tail of the Human Immunodeficiency Virus Type 1 p6GagProtein Produces a Mutant That Fails To Package Its Envelope Protein

Author

Ott, David E., Chertova, Elena N., Busch, Laura K., Coren, Lori V., Gagliardi, Tracy D., and Johnson, Donald G.

Abstract

ABSTRACTThe p6Gagprotein of human immunodeficiency virus type 1 (HIV-1) is produced as the carboxyl-terminal sequence within the Gag polyprotein. The amino acid composition of this protein is high in hydrophilic and polar residues except for a patch of relatively hydrophobic amino acids found in the carboxyl-terminal 16 amino acids. Internal cleavage of p6Gagbetween Y36and P37, apparently by the HIV-1 protease, removes this hydrophobic tail region from approximately 30% of the mature p6Gagproteins in HIV-1MN. To investigate the importance of this cleavage and the hydrophobic nature of this portion of p6Gag, site-directed mutations were made at the minor protease cleavage site and within the hydrophobic tail. The results showed that all of the single-amino-acid-replacement mutants exhibited either reduced or undetectable cleavage at the site yet almost all were nearly as infectious as wild-type virus, demonstrating that processing at this site is not important for viral replication. However, one exception, Y36F, was 300-fold as infectious the wild type. In contrast to the single-substitution mutants, a virus with two substitutions in this region of p6Gag, Y36S-L41P, could not infect susceptible cells. Protein analysis showed that while the processing of the Gag precursor was normal, the double mutant did not incorporate Env into virus particles. This mutant could be complemented with surface glycoproteins from vesicular stomatitis virus and murine leukemia virus, showing that the inability to incorporate Env was the lethal defect for the Y36S-L41P virus. However, this mutant was not rescued by an HIV-1 Env with a truncated gp41TMcytoplasmic domain, showing that it is phenotypically different from the previously described MA mutants that do not incorporate their full-length Env proteins. Cotransfection experiments with Y36S-L41P and wild-type proviral DNAs revealed that the mutant Gag dominantly blocked the incorporation of Env by wild-type Gag. These results show that the Y36S-L41P p6Gagmutation dramatically blocks the incorporation of HIV-1 Env, presumably acting late in assembly and early during budding.

Published
1999
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33. Ubiquitin Is Covalently Attached to the p6GagProteins of Human Immunodeficiency Virus Type 1 and Simian Immunodeficiency Virus and to the p12GagProtein of Moloney Murine Leukemia Virus

Author

Ott, David E., Coren, Lori V., Copeland, Terry D., Kane, Bradley P., Johnson, Donald G., Sowder, Raymond C., Yoshinaka, Yoshiyuki, Oroszlan, Stephen, Arthur, Larry O., and Henderson, Louis E.

Abstract

ABSTRACTHost proteins are incorporated into retroviral virions during assembly and budding. We have examined three retroviruses, human immunodeficiency virus type 1 (HIV-1), simian immunodeficiency virus (SIV), and Moloney murine leukemia virus (Mo-MuLV), for the presence of ubiquitin inside each of these virions. After a protease treatment to remove exterior viral as well as contaminating cellular proteins, the proteins remaining inside the virion were analyzed. The results presented here show that all three virions incorporate ubiquitin molecules at approximately 10% of the level of Gag found in virions. In addition to free ubiquitin, covalent ubiquitin-Gag complexes were detected, isolated, and characterized from all three viruses. Our immunoblot and protein sequencing results on treated virions showed that approximately 2% of either HIV-1 or SIV p6Gagwas covalently attached to a single ubiquitin molecule inside the respective virions and that approximately 2 to 5% of the p12Gagin Mo-MuLV virions was monoubiquitinated. These results show that ubiquitination of Gag is conserved among these retroviruses and occurs in the p6Gagportion of the Gag polyprotein, a region that is likely to be involved in assembly and budding.

Published
1998
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35. Letters.

Author

Smith, William G., Sargent, Ross L., Johnson, Donald G., Sullivan, Paul M., Davies, Gregory L., Brazeman, Cary, Miller, Austin E., Goldwater, Barry, Malott, Robert H., Proxmire, William, Braun, Christof, Petersen, Mo, Buckwalter, Stefan, Homer, Bill, and Cameron, Susan

Subjects
LETTERS to the editor, ROBOTS, MILITARY spending, MILITARY budgets, MILITARY vehicles
Abstract

Several letters to the editor are presented in response to articles in previous issues including "Here Come the Robots" in the March 7, 2010 issue, another on the analysis of defense spending, and the commentary on Bradley Fighting Vehicle.

Published
1983

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