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A 28-kDa endoglucanase was isolated from the culture filtrate of Phanerochaete chrysosporium strain K3 and named EG 28. It degrades carboxymethylated cellulose and amorphous cellulose, and to a lesser degree xylan and mannan but not microcrystalline cellulose (Avicel). EG 28 is unusual among cellulases from aerobic fungi, in that it appears to lack a cellulose-binding domain and does not bind to crystalline cellulose. The enzyme is efficient at releasing short fibres from filter paper and mechanical pulp, and acts synergistically with cellobiohydrolases. Its mode of degrading filter paper appears to be different to that of endoglucanase I from Trichoderma reesei. Furthermore, EG 28 releases colour from stained cellulose beads faster than any other enzyme tested. Peptide mapping suggests that it is not a fragment of another known endoglucanases from P. chrysosporium and peptide sequences indicate that it belongs to family 12 of the glycosyl hydrolases. EG 28 is glycosylated. The biological function of the enzyme is discussed, and it is hypothesized that it is homologous to EG III in Trichoderma reesei and the role of the enzyme is to make the cellulose in wood more accessible to other cellulases.

The positions of the disulfide bridges in toxin II of Androctonus australis Hector were investigated using proteolytic enzymes. The resulting peptides were separated by column and paper chromatography and high-voltage electrophoresis. Determination of the amino acid compositions of the cystine-containing peptides or their oxidized derivatives and, when necessary, dansyl Edman degradation allowed to locate the disulfide bonds in the toxin. The four disulfide bridges were found to link the half-cystine residues number 12 and 63, 16 and 36, 22 and 46, 26 and 48. These positions are probably the same in all scorpion neurotoxins.

The primary structure of sheep para-xA-casein, the N-terminal portion of x-casein, was established. The reduced alkylated protein was subjected to digestion with trypsin. The resulting soluble peptides were purified by a combination of Dowex 1 X2 chromatography and electrophoresis and chromatography on paper; the core peptides were solubilized in 50% formic acid and filtered on Sephadex G-50. The amino-acid sequence of these peptides was determined chiefly with a Sequencer. Alignment of the tryptic peptides into a single chain containing 105 amino acids was determined from basic overlap peptides (tryptic core peptides with several basic amino acids; chymotryptic peptides). Some comparisons were achieved with cow para-xa-casein. %-Casein is the principal casein fraction affected by chymosin (or rennin) in the primary phase of the milk clotting process [ 11. The group of Jollbs established already in 1965 that during this enzymic reaction, a Phe -+ Met linkage was specifically split in cow as well as in sheep x-caseins [2-41. An insoluble part, para-x-casein (N-terminal moiety of x-casein), was from Merck or Prolabo except those employed for the Sequencer which were purchased from Socosi (94100Saint Maur, France) and 4-sulfophenylisothiocyanate from Pierce.

The covalent structures of the four highly homologous Fc-binding regions in protein A, regions D, A, B, and C, have been studied by enzymic fragmentations of previously isolated fragments originating from these regions and subsequent isolation of the generated peptides by ion-exchange chromatography, molecular-sieve chromatography, high-voltage paper electrophoresis and paper chromatography. The complete sequence of region B was elucidated by combining the results of Edman degradations on isolated fragment B peptides with the previously reported N-terminal sequence of the same fragment. Furthermore, Edman degradations of fragment D, A and C peptides differing from the region B sequence provided the structures of subregions not identical to corresponding subregions within region B. Thus, it is possible to propose a highly probable covalent structure for the N-terminal 27000-molecular-weight portion of protein A responsible for the IgG-Fc-binding activities. However, it was not possible to assign the activities to specific structures within the regions. The sequence data indicate that not only mutual homology between the four regions exists, but also internal homologies within the regions. Furthermore, the data strongly supports the hypothesis of a stepwise gene fusion procedure being involved in the evolution of the protein.

The isolation and amino-acid and carbohydrate composition of three tryptic glycopeptides, containing 16,17 and 20 amino-acid residues, respectively, from the neuraminidase-treated major form of human ceruloplasmin have been described earlier. It has also been suggested that the peptides possibly represent all of the carbohydrate-binding sites in the protein. The present paper describes the amino-acid sequences of these peptides as obtained by stepwise Edman degradation and carboxypeptidase digestions of the whole peptides and their fragments after cleavage by chymotrypsin, pepsin and thermolysin. The results confirm that the carbohydrate in all cases is attached via an asparagine (or aspartic acid) residue, that is followed by an X-Thr/Ser sequence. No sequence homologies are found when the peptides are compared to each other or to other glycopeptides of known sequence.

The partial amino acid sequence of dihydrofolate reductase (DHFR, EC 1.5.1.3) from human KB/6b cells has been determined by using 3.5 mg of protein. Peptides covering the entire polypeptide chain were recovered from preparative peptide maps generated by the combination of paper chromatography and electrophoresis at pH 4.4 Peptide maps from mouse L1210 DHFR were also generated for comparison. Amino acid sequence of 75% of the 186 amino acid residues in the polypeptide chain of human KB/6b DHFR was obtained from Edman degradations and the remaining sequence was deduced from the amino acid compositions, from electrophoretic mobilities of related peptides and from the sequence homologies with other known mammalian DHFR sequences. A comparison of the proposed human DHFR sequence with the previously known sequences of mouse enzyme [Stone, et al. (1979) J. Biol. Chem. 245, 480-488] indicates that 18 differences are located in the established sequence of 139 residues and that 5 additional differences are in the tentative sequence of the remaining 47 amino acids. Kinetic properties of human KB/6b and mouse L1210 DHFR, which were determined in parallel experiments, are also compared. The possible structural-functional relationships between human and mouse DHFR are discussed.

The amino acid sequence of the porcine vasoactive intestinal octacosapeptide is His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-L ys-Lys-Tyr-Leu-Asn-Ser-Ile-Leu-Asn-NH2. Its amino acid residues 1, 2, 6 and 7, counted from the N-terminus, are identical to those in the corresponding positions in both porcine glucagon and secretin. The residues in positions 3, 12, 13, 14 and 23 are identical to those in secretin, but not in glucagon, and position 10 is occupied by a tyrosyl and position 28 by an asparaginyl residue, like in glucagon but not in secretin. If in addition to identical amino acid residues also chemically similar residues, such as isoleucine in position 26 of the octacosapeptide, as compared to leucine in secretin and glucagon, are taken into consideration then the similarity between these three polypeptides is still more evident. At a more remote level there is some structural resemblance also between these peptides and the other four peptides from the intestinal wall, cholecystokinin-pancreozymin, motilin, the gastric inhibitory peptide and substance P, the structures of which are known. The elucidation of the structure of the octacosapeptide was facilitated by the finding that pancreatic kallikrein preferentially cleaved only one of the three bonds in its N-terminal cyanogen bromide heptadecapeptide that are susceptible to cleavage with trypsin.

Peptide studies on two acidic proteins, A1 and A2, from 50-S ribosomes of Escherichia coli indicate a closely related primary structure. 1 Amino acid compositions of the tryptic peptides of the two proteins are identical, with exception of the amino terminal peptide. 2 The N-terminal amino acid sequence of A2-protein is Ser-Ile-Thr-Lys, while that of A1-protein is N-acetyl-Ser-Ile-Thr-Lys. 3 The estimated number of 120 amino acid residues in each polypeptide chain is consistent with the physical molecular weight estimate. 4 In 50% of the polpeptide chains, in both A1 or A2-protein, a specific lysine residue is replaced by ɛ-N-monomethyl-lysine.

Cleavage with cyanogen bromide was employed to investigate the N-terminal amino acid sequence of the λ-chains of normal porcine immunoglobulin. The N-terminal homoserine-containing nonapeptide was isolated from all fractions of the λ-chains in a yield of 60% of theory. Its amino acid sequence was determined by mass spectrometry and was found to be uniform. Other homoserine-containing fragments were obtained from the cyanogen bromide hydrolyzate of the λ-chains with split disulfide bonds. Partial amino acid sequence of these fragments provided evidence that methionine in position 9 is present in more than 60% of variants and obviously has an invariant character. Variants of the λ-chains exist (by estimate not more than 15% of the total λ-chains) which, in addition to the invariant methionine residue in position 9, possess a variable methionine residue in the section between positions 46 and 51. The data obtained indicate that the sequence of 23 amino acid residues from the N-terminus of porcine λ-chains is uniform with the exception of a single replacement (in position 13). Moreover, in comparison with the sequence of λ-chains of man, mouse and birds, the sequence displays several species-specific replacements and a deletion of threonine which occupies position 5 in the chains of the other species. In the pig, the λ-chains represent the predominant type of light chains (some 70%). Hence it follows that some 50% of the light chains in this species possess a uniform amino acid sequence in the N-terminal section. These facts are difficult to reconcile with the germline theories of genetic control so that mechanisms of somatic diversification of immunoglobulins must be envisaged.

The primary structures of the ribosomal proteins A1 (= L7) and A2 (= L12) have been elucidated. Comparison of the two amino acid sequences confirms earlier studies by us (1972) which indicated that the two proteins are identical except that A1 possesses an N-terminal acetyl group. Sequencing of tryptic and chymotryptic peptides was accomplished primarily by automatic solid-phase Edman degradation of 50- to 70-nanomole peptide samples. A large tryptic peptide T1Phe, which could not be sequenced by this method, was fragmented with elastase and its sequence mainly derived by conventional methods. The sequence of the first 51 residues of the nonacetylated A2-protein was obtained by Edman degradation in the Beckman sequencer. A-protein comprises three distinct regions: I (residues 1—55), which is negatively-charged and hydrophobic, II (56—81), which is positively charged, and III (82—120), which is negatively charged and hydrophilic. α-Helix promoting residues are located primarily in regions I and III. ɛ-N-Monomethyllysine, which occurs in 50% of the A1 and A2 chains is located in the more flexible region II at position 81. The distinctive clustering of hydrophobic and charged residues is quite remarkable and suggests that in situ certain of these regions may contain a binding site for components involved in peptide chain elongation.

The active thiol group of lombricine kinase from Lumbricus terrestris muscle was labelled with N-ethyl-[1-14C]maleimide. The resulting inactivated N-ethyl-[1-14C]succinimido enzyme was then subjected to tryptic hydrolysis. The peptide containing the labelled essential thiol group was isolated and found to contain: Leu-Gly-Tyr-Ile-Thr-[14C]Cys-Pro-Gly-Ser-Asn-Leu-Gly-Thr-Leu-Arg. The amino acid sequence around this thiol group was very similar with that of homologous ATP: guanidine phosphotransferases previously studied, arginine kinase from Homarus vulgaris muscle, creatine kinases from ox brain and ox muscle and from rabbit muscle. In addition among the other enzymes of this group, lombricine kinase is of special interest since it is the only dimeric enzyme of molecular weight ≃ 80000 which possesses only one essential thiol group and one nucleotide binding site per two subunits.

For the elucidation of the amino-acid sequence of the carboxyl-terminal region of soybean trypsin inhibitor (Kunitz), fragments C and D were digested with trypsin, and the resulting peptides were separated by ion-exchange chromatography on Dowex 50X2 or by gel nitration on Bio-Gel P-4. Further fractionation and purification of the peptides were performed by ion-exchange chromatography on Dowex 1X2, by gel filtration on Bio-Gel P-2 or by high-voltage paper electrophoresis at pH 1.9 and 3.6. Three peptides were obtained in pure form from fragment C and ten peptides from fragment D, and their amino-acid sequences were determined by the direct Edman method and by carboxy-peptidase digestion technique. Overlapping peptides necessary for the alignment of the tryptic peptides from fragment D were obtained from a chymotryptic hydrolysate of fragment D. Nine main peptides and nine minor peptides were obtained. The amino acid composition and the partial amino-acid sequence of the 18 chymotryptic peptides of fragment D made it possible to establish the amino-acid sequence of the carboxyl-terminal region of the inhibitor. The complete amino-acid sequence of soybean trypsin inhibitor (Kunitz) deduced here was compared with that of Bowman-Birk inhibitor, another well-known soybean proteinase inhibitor.

A short glycopeptide was isolated from bovine χ-casein by enzymic digestions, filtrations on Sephadex G-25 and was electrophoretically homogeneous. An O-glycosidic linkage was characterized between a residue of threonine and N-acetylgalactosamine. By chemical and enzymic proce- dures, the following formula was established: where NeuNAc =N-acetylneuraminic acid. The phosphoserine residue of χ-caseinoglycopeptide was characterized in the short glycopeptide which was localized in the C-terminal part of χ-casein. Thr-X-Pro might be suggested as “code sequence” for glycopeptides containing an O-glycosidic linkage.

1 Adenylate kinase (ATP:AMP phosphotransferase) has been purified 490-fold from porcine muscle with a final yield of 60 mg/kg muscle. 2 The amino-acid composition is Asp11, Asn2, Thr14, Ser11, Glu19, Gln6, Pro6, Gly19, Ala8, Cys2, Val17, Met6, Ile9, Leu18. Tyr7, Phe5, Lys21, His2, Arg11. 3 The protein molecule is a single polypeptide chain of 194 amino-acid residues with an acetyl-methionine at the N-terminus and a lysine residue at the C-terminus. 4 Cyanogen bromide cleavage of carboxymethylated adenylate kinase yielded six fragments which were further degraded by using trypsin, chymotrypsin, thermolysin, subtilisin or α-protease. Sequence data on the resulting peptides are summarized in the present report, full details are given in a supplementary paper which has been deposited at CNRS from where copies can be obtained. 5 The primary structure of porcine adenylate kinase is: Ac-Met-Glu-Glu-Lys-Leu-Lys-Lys-Ser-Lys-Ile10-Ile-Phe-Val-Val-Gly-Gly-Pro-Gly - Ser-Gly20-Lys-Gly-Thr-Gln-Cys-Glu-Lys-Ile-Val-Gln30-Lys-Tyr-Gly-Tyr-Thr-His-Leu-Ser-Thr-Gly40-Asp-Leu-Leu-Arg-Ala-Glu-Val-Ser-Ser-Gly50-Ser-Ala-Arg-Gly-Lys-Met-Leu-Ser-Glu-Ile60-Met-Glu-Lys-Gly-Gln-Leu-Val-Pro-Leu-Glu70-Thr-Val-Leu-Asp-Met-Leu-Arg-Asp-Ala-Met80-Val-Ala-Lys-Val-Asp-Thr-Ser-Lys-Gly-Phe90-Leu-Ile-Asp-Gly-Tyr-Pro-Arg-Glu-Val-Lys100-Gln-Gly-Glu-Glu-Phe-Glu-Arg-Lys-Ile-Gly110-Gln-Pro-Thr-Leu-Leu-Leu-Tyr-Val-Asp120-Ala-Gly-Pro-Glu-Thr-Met-Thr-Lys-Arg-Leu-Leu130-Lys-Arg-Gly-Glu-Thr-Ser-Gly-Arg-Val-Asp140-Asp-Asn-Glu-Glu-Thr-Ile-Lys-Lys-Arg-Leu150-Glu-Thr-Tyr-Tyr-Lys-Ala-Thr-Glu-Pro-Val160-Ile-Ala-Phe-Tyr-Glu-Lys-Arg-Gly-Ile-Val170-Arg-Lys-Val-Asn-Ala-Glu-Gly-Ser-Val-Asp180-Asp-Val-Phe-Ser-Gln-Val-Cys-Thr-His-Leu190-Asp-Thr-Leu-Lys.

A partial sequence of the manganese-containing superoxide dismutase from Bacillus stearothermophilus has been determined by mass spectrometry. A new fragmentation reaction at N-terminal proline is described and an 'in-chain' fragmentation, also occurring at proline, has been observed. There is some evidence that the latter cleavage may also occur at other residues. Some differences from the classically determined sequence are reported, and the validity of these observations is discussed.

The complete primary structure of mouse prolactin has been established on the basis of tryptic peptides from cyanogen-bromide-treated, S-carboxymethylated mouse prolactin and Staphylococcus-aureus-protease-cleaved overlaps, which were sequenced by manual liquid-phase and solid-phase Edman degradation. Three disulfide bonds were assigned to Cys-4-Cys-9, Cys-56-Cys-172, and Cys-189-Cys-197 by digestion of intact prolactin with S. aureus protease. One of the characteristics to date is replacement of Trp-89, which is commonly present among prolactin, growth hormone and choriomammotropin, by serine. It was suggested, by comparison with five other prolactins, five growth hormones and human choriomammotropin, that Asp-18, His-25, Ser-60 and Thr-63 are essential to lactogenic activity.

Tryptic and chymotryptic digestion of peptide B, the N-terminal fragment obtained by cyanogen bromide cleavage of thioredoxin, provided the information required to determine the contiguity of the peptic fragments studied previously. The complete sequence of the 37 residues of peptide B could thus be established. Peptide B contains the active center of thioredoxin. Its amino acid sequence was found to be: . This sequence supports earlier conclusions drawn from fluorescence studies of thioredoxin, which indicated a close relationship between one or both tryptophan residues and the disulfide bridge of the active site. Peptide maps of the tryptic digests of carboxymethylated thioredoxin and of the two cyanogen bromide fragments are described. Amide nitrogen analyses of thioredoxin and the two cyanogen bromide fragments demonstrate that all seven amide groups of thioredoxin are localized in the C-terminal fragment (peptide A).

A comparison has been made of the sequence of the tyrosine-containing tryptic peptide derived from the purified, unfractionated, lysine-rich histone complement of the calf thymus, rat thymus and calf liver. Two tyrosine-containing peptides, one of which is a fragment of the other, have been obtained from each tissue. The major tyrosine-containing peptide was isolated by a single electrophoretic step in about a 50%, yield. The results indicate that the sequence of amino acids around the single tyrosine present in the lysine-rich molecule is constant from tissue to tissue. However, this sequence varies among the molecular species comprising the lysine-rich histone complement of a single tissue. Within a tissue, a conservative amino acid replacement in the residue penultimate to tyrosine (from the amino terminus) has been detected. The sequence of the tyrosine-containing region was found to be Lys-Ala-Leu-Ala-AlaGly-Gly-Tyr-Asp-Val-Glu-Lys.

The amino acid sequences of two rat C-peptides corresponding to two rat proinsulins have been elucidated. Both C-peptides have 31 amino acids. There are differences in two positions, namely, in position 8 where rat-I has a proline and rat-II an alanine residue, and in position 17 where rat-I has a glutamic acid, rat-II a glycine residue. The additional acidic residue in rat-I C-peptide is counteracted by the additional basic residue in the insulin moiety of rat-I proinsulin (lysine B 29), which provides the two proinsulins with the same net charge at neutral pH. The amino acid sequences are: The rat C-peptides contain threonine and arginine, neither of which is present in the C-peptides of man, pig and ox. A comparison of the 5 sequences shows only 10 identical positions out of 31.

The mureins of several micrococci and coryneform organisms contain more than one mole of glutamic acid per mole of meso-diaminopimelic acid (Dpm). The amino acid sequence of these mureins was studied. The peptide subunit consists of Mur-l-Ala-γ-d-Glu-meso-Dpm-d-Ala, where Mur = muramic acid. The γ-carboxyl group of glutamic acid is substituted in most cases by a glycine amide. The cross-linkage of the peptide subunits is performed by the dipeptide γ-d-glutamyl-d-glutamic acid. This peptide is bound by the γ-carboxyl group of the C-terminal glutamic acid to the amino group of diaminopimelic acid and to the carboxyl group of d-alanine of an adjacent peptide subunit by the amino group of the N-terminal glutamic acid. The mureins of the micrococci studied contain only one mole of amide ammonia per mole of diaminopimelic acid and this is bound to glycine. In the mureins of the coryneform organisms a second mole of amide ammonia was found which is probably bound to diaminopimelic acid. The murein of Staphylococcus lactis CCM 2432 lacks amide ammonia as well as glycine.

Peptide A, the C-terminal cyanogen bromide fragment of thioredoxin, was degraded with chymotrypsin and pepsin. Partial sequences of 12 chymotryptic and 6 peptic peptides and the N-terminal tryptic peptide of trifluoro-acetylated peptide A were determined. The results were used to establish the order of the previously described tryptic peptides of peptide A and lead to the complete amino acid sequence of peptide A. Previous experiments had established the amino acid sequence of peptide B, the N-terminal cyanogen bromide fragment of thioredoxin and the present results thus give the complete amino acid sequence of thioredoxin from Escherichia coli B. The molecule contains 108 residues in a single polypeptide chain with a molecular weight of 11,657 as calculated from the sequence. The functional group of the protein occurs in position 32 to 35 and consists of a disulfide bridge formed by two half-cystine residues separated by a glycine and a proline residue. No metals were found as part of the functional group.

A purified glycoprotein with blood-group-A specificity, was digested with insoluble pronase to give a serologically active product enriched in peptide-bonded serine and threonine residues; this was degraded with 0.25 M sulphuric in glacial acetic acid for 24 h. The resultant N-acetylgalactosaminyl-peptides were hydrolysed with 0.2 M hydrochloric acid for 24 h at 110°C. Fractionation of the products on Sephadex G-10, followed by preparative separation on an amino-acid analyser and paper electrophoresis at pH 1.9 yielded the following homogeneous oligopeptides; one tripeptide with the N-terminal sequence Thr-Thr-Ser, three tetrapeptides with the sequences, Thr-Ser-Thr-Ser, Thr-Pro-Thr-Ser and Pro-Thr-Thr-Ser, one pentapeptide with the sequence Thr-Pro-Thr-Ser-Ser, one hexapeptide with the sequence Pro-Thr-Thr-Thr-Pro-Ser and one heptapeptide with the sequence Ala-Pro-Thr-Thr-Ser-Gly-Ser. Galactosamine was present in several of these fragments and the hexapeptide and heptapeptide both contained sufficient of this sugar for all the serine and threonine residues to be glycosylated. The following five tetrapeptides sequences were deduced from mixtures of two peptides which differed by the amino-acid substituent at only one position in the chain; Pro-Thr-Ala-Ser, Thr-Thr-Pro-Ser, Thr-Thr-Ala-Ser, Ser-Pro-Thr-Ser, and Ser-Ala-Thr-Ser. A tripeptide mixture which differed only in the nature of the third amino acid yielded the following three tripeptide sequences: Pro-Thr-Ser, Pro-Thr-Gly and Pro-Thr-Ala. These peptides do not indicate a clearly defined amino-acid sequence surrounding the glycosylated hydroxy amino acids but establish that in the human blood-group-specific glycoproteins there is close packing of the serine and threonine residues in the region of the peptide moiety carrying the carbohydrate chains.

Histidine decarboxylase from Micrococcus sp.n. was carboxymethylated and two types of subunits, I and II, were separated in excellent yield by exclusion chromatography on Sephadex G-100 in 8 M urea. Total compositions, number of tryptic peptides and N-terminal groups of the subunits were analyzed. The larger subunit I is composed of all amino acids commonly found in proteins and has a blocked N-terminal residue, whereas the smaller subunit II does not contain proline, histidine or cysteine and has N-terminal methionine. The number of tryptic peptides detected in peptide mapping experiments of subunit I is about 27 and that of subunit II is about 15. These figures are in good agreement with the total number of lysine and arginine residues determined by amino acid analysis, if subunit I contains about 270 residues, corresponding to a molecular weight of 29000, and subunit II about 70 residues, corresponding to a molecular weight of 7000. It is concluded that histidine decarboxylase contains two apparently homogeneous but completely different polypeptide chains and that the native enzyme of molecular weight 110000 is a hexamer with three subunits of each type.

Highly purified calf thymus ALK-histone (histone rich in alanine, lecine and lysine) was isolated from F2a2 histone fraction by ion-exchange chromatography on Biorex 70 followed by gel filtration chromatography on Sephadex G-100. Peptides obtained by enzymatic hydrolyses (trypsin, chymotrypsin, thermolysin) of native or maleylated protein were fractionated by ion-exchange chromatography on Chromobeads P. Thermolysin peptides which account for 127 of the 129 residues of the protein provide overlaps of tryptic and chymotryptic peptides and led us to establish the complete amino-acid sequence of ALK-histone as follows: Ser1Gly-Arg-Gly-Lys-Gln-Gly-Gly-Lys-Ala-10Arg-Ala-Lys-Ala- Lys-Thr-Arg-Ser-Ser-Arg20-Ala-Gly-Leu-Gln-Phe-Pro-Val-Gly-Arg-Val30-His-Arg-Leu-Leu-Arg-Lys-Gly-Asn-Tyr-Ala40-Glu-Arg-Val-Gly-Ala-Gly-Ala-Pro-Val-Tyr50-Leu-Ala-Ala-Val-Leu-Glu-Tyr-Leu-Thr-Al60-Glu-Ile-Leu-Glu-Leu-Ala-Gly-Asn-Ala-Ala70-Arg-Asp-Asn-Lys-Lys-Thr-Arg-Ile-Ile-Pro80-Arg-His-Leu-Gln-Leu-Ala-Ile-Arg-Asn-Asp90-Glu-Glu-Leu-Asn-Lys-Leu-Leu-Gly-Lys-Val100-Thr-Ile-Ala-Gln-Gly-Gly-Val-Leu-Pro-Asn110-Ile-Gln-Ala-Val-Leu-Leu-Pro-Lys-Lys-Thr120Glu-Ser-His-His-Lys-Ala-Lys-Gly-Lys129. The amino end is acetylated. The sequence of ALK-histone is characterized by two hydro-phobic regions, the first from Val-43 to Ala-70 and the second from Val-100 to Pro-117 and presents many repetitive or analogous sequences. The NH2-terminal sequence of ALK-histone is highly basic and shows a remarkable analogy with that of GRK-histone. A cluster of five basic residues His-His-Lys-Ala-Lys-Gly-Lys is present at the COOH-terminal end.

The amino acid sequence of component 0.62, a protein derived from wool keratin, with molecular weight of 6950, rich in glycine and aromatic residues, has been determined. The protein contains no lysine, histidine, glutamic acid, isoleucine or methionine. Of the total residues, more than 50% are glycine and aromatic amino acids. The sequence contains two sections rich in glycine, (Gly-X)3 and (Gly-X)4, which comprise 22% of the sequence.

Peptide B, the N-terminal fragment of thioredoxin obtained by cyanogen bromide treatment was aminoethylated and digested with pepsin. Eight peptides were separated by high voltage paper electrophoresis and chromatography and characterized with respect to amino acid sequence. The results account for all 37 residues of peptide B. The N-terminal sequence of peptide B was determined as: Ser-Asp-Lys-Ile-Ile-His-Leu-Thr-Asp-Asp-Ser-Phe.