Showing papers on "Peptide sequence published in 1974"

Vitamin K Dependent Modifications of Glutamic Acid Residues in Prothrombin

Abstract: A tetrapeptide, residues 6 to 9 in normal prothrombin, was isolated from the NH2-terminal, Ca2+-binding part of normal prothrombin. The electrophoretic mobility of the peptide was too high to be explained entirely by its amino-acid composition. According to 1H nuclear magnetic resonance spectroscopy and mass spectrometry, the peptide contained two residues of modified glutamic acid, γ-carboxyglutamic acid (3-amino-1,1,3-propanetricarboxylic acid), a hitherto unidentified amino acid. This amino acid gives normal prothrombin the Ca2+-binding ability that is necessary for its activation. Observations indicate that abnormal prothrombin, induced by the vitamin K antagonist, dicoumarol, lacks these modified glutamic acid residues and that this is the reason why abnormal prothrombin does not bind Ca2+ and is nonfunctioning in blood coagulation.

Structure of the porcine vasoactive intestinal octacosapeptide. The amino-acid sequence. Use of kallikrein in its determination.

Abstract: 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.

The Amino-Acid Sequence of the Alkali Light Chains of Rabbit Skeletal-Muscle Myosin

Abstract: The amino-acid sequence of the alkali light chain 1 (Al) of rabbit skeletal muscle myosin has been determined and compared with the sequence of the smaller but related alkali light chain 2 (A2). The molecular weights of the two proteins calculated from these sequence determinations are 20700 and 16500, respectively. The results show that the two proteins have identical sequences over their C-terminal141 residues. There is an additional sequence of 41 residues at the N-terminal end of A1 which accounts for the extra 4000 molecular weight. Between this additional sequence and the sequence common to both proteins are eight amino-acid residues. Comparison of the sequences of these eight residues in A1 and A2 reveals five amino-acid substitutions. Thus in spite of the very extensive homology between the two proteins, these substitutions indicate that there must be two RNA coding sequences for these light chains in rabbit fast muscle myosin. Rabbit skeletal muscle myosin contains two heavy chains of molecular weight about 200000 [l 21 and four light chains of molecular weight about 20000 [3]. Two chemical classes of light chains have been characterised by their thiol peptides [4] and reaction of myosin with 5,5’-dithiobis(2-nitrobenzoic acid) (Nbs,) selectively dissociated a substantial proportion of one of these light chains without significant effect on the myosin ATPase activity. This light chain has been termed the “Nbs, light chain” l. The remaining light chains cannot be dissociated without total loss of ATPase activity and these were termed the “alkali light chains”, since they were first shown to be released under alkaline conditions [5]. Gel electrophoresis of myosin in the presence of sodium dodecylsulphate shows the presence of three light chain components with apparent molecular weights of 25000, 18000 and 16000 [3]. The 18000-M, component corresponds to the Nbs, light chain and the other two components are classified as alkali light chains since they both contains the single thiol sequence characteristic of this class of light chains in fast muscle myosin [6,7]. The extent of sequence homology between alkali light chain 1 (Al, Mr = 25000) and alkali light chain 2 (A2, Abbreviation. Nbs,, 5,5’-dithiobis(2-nitrobenzoic acid). Nomenclature. The term “alkali light chain” is based on the observation that these proteins are dissociated from myosin in alkali [5]. Other terminology used elsewhere includes LC1(= Al) and LC3 (= A2) [26] and OL and y chains [29]. 1 The “Nbs, light chain” was previously called the “DTNB light chain” [4]. Mr = 16000) was examined by peptide mapping of tryptic digests of the two proteins. Peptides from both proteins stained selectively for arginine, tyrosine and histidine had identical mobilities in the two-dimensional maps, and all the peptides present in A2 could be found in corresponding positions in Al. Such differences as there were could be accounted for by additional peptide material in Al, though the amino-acid compositions indicated minimum molecular weights of 21000 for A1 and 17000 for A2, a difference of 4000 instead of the 8000 estimated from apparent molecular weights determined by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulphate. From these results it was concluded that either A2 was a degraded fragment of A1 or the two proteins showed an exceptionally high degree of homology. The relative constancy in the amounts of A1 and A2 in rabbit myosin prepared under a variety of conditions together with observations that both components are found in myosin from chicken breast and leg muscles [S], and the fast skeletal muscle of pig, sheep and cat, make it unlikely that A2 arises as a result of adventitious proteolytic activity. Nevertheless we could not rule out a specific cleavage occurring in the polypeptide chains as a consequence of post-translational modification or during the myosin assembly process. For this reason detailed sequence analysis of both A1 and A2 has been carried out to investigate the relationship between them and show whether they represent products of different genes. Part of the results of this work have been published previously [9].

The Complete Amino‐Acid Sequence of Non‐Immunolobulin Amyloid Fibril Protein AS in Rheumatoid Arthritis

Abstract: The primary structure of a non-immunoglobulin amyloid protein AS has been determined. The protein was found to consist of 76 amino acid residues corresponding to a molecular weight of 9145. The sequence analysis showed clearly that the protein was homogeneous. A characteristic distribution of hydrophobic amino acids was observed and suggested as being of importance for the ability of this protein to form fibrils. A comparison of the protein with other amyloid protein AS showed a high degree of variability, particularly in the carboxyl-terminal region.

Comparative specificity of microbial proteinases.

Abstract: The specificities of various acid proteinases from fungi or yeasts were comparatively determined using synthetic peptides as substrates. Swine pepsin was used in a comparative study. The pepstatin-sensitive proteinases exhibited their specificity against aromatic or hydrophobic amino acid residues on both sides of the splitting point in peptide substrates, and some differences were observed depending upon their source. Some of the enzymes, possessing trypsinogen-activating ability, also showed their specificity against L -lysine residue on the carboxyl side of the splitting point. In comparison, a pepstatin-insensitive enzyme A from Scytalidium showed considerably broad specificity. The hydrolysis of peptides by pepstatin-sensitive enzymes was markedly accelerated by elongating the peptide chain by three amino acid residues on both sides of the splitting point, while the elongation of two residues produced the same effect with the pepstatin-insensitive enzyme. Thus, Z-(Ala)2-Lys-(Ala)3 was most susceptible (↑ shows the bond split) to the former enzymes possessing trypsinogen-activating ability, and Z-Phe-Leu-Ala-Ala for the latter one. Another pepstatin-insensitive enzyme from Scytalidium showed negligible activity on the peptides used in this study.

The Amino‐Acid Sequence of Porcine Adenylate Kinase from Skeletal Muscle

Abstract: 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.

Comparison of predicted and experimentally determined secondary structure of adenyl kinase

Abstract: IT is generally accepted that the action of a protein cannot be understood until its three-dimensional structure is known. At present, X-ray analysis of protein crystals is the only method of obtaining such structural information. It is to be feared, however, that many important proteins will never give suitable crystals so that one is obliged to consider other approaches to structure elucidation. Renaturation experiments indicated1–4 that the three-dimensional structure of many if not all proteins is a unique function of their amino acid sequence. Therefore, in principle one should be able to determine these structures by using only the information contained in the sequence. A first step in this direction is the prediction of secondary structures (α helices, β pleated sheets, β bends) in globular proteins from amino acid sequences. Several prediction schemes have been devised to this end5–23. It is the aim of this paper to demonstrate directly the current standing of such methods.

Amino acid sequence of the smaller basic protein from rat brain myelin

Abstract: 1. The complete amino acid sequence of the smaller basic protein from rat brain myelin was determined. This protein differs from myelin basic proteins of other species in having a deletion of a polypeptide of 40 amino acid residues from the centre of the molecule. 2. A detailed comparison is made of the constant and variable regions in a group of myelin basic proteins from six species. 3. An arginine residue in the rat protein was found to be partially methylated. The ratio of methylated to unmethylated arginine at this position differed from that found for the human basic protein. 4. Three tryptic peptides were isolated in more than one form. The differences between the two forms of each peptide are discussed in relation to the electrophoretic heterogeneity of myelin basic proteins, which is known to occur at alkaline pH values. 5. Detailed evidence for the amino acid sequence of the protein has been deposited as Supplementary Publication SUP 50029 at the British Library (Lending Division) (formerly the National Lending Library for Science and Technology), Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1973) 131, 5.

Amino acid sequence of rabbit muscle aldolase and the structure of the active center.

Abstract: Elucidation of the amino acid sequence of fructose-1,6-bis-phosphate aldolase from rabbit muscle has made it possible to assign the positions of the functional groups known to play specific roles in the catalytic activity, and also to locate the buried, exposed, and active site cysteine residues. The results indicate that the middle portion of the polypeptide chain, including Cys-134, Cys-149, Cys-177, and Cys-l99, is buried in the native structure, with regions containing Cys-72, Lys-107, Lys-227, Cys-336, His-359, and the COOH-terminal residue (Tyr-361) folded into the active center of the enzyme, at or near the surface of the enzyme molecule.

Topological comparison of adenyl kinase with other proteins

Abstract: A COMBINATION of amino acid sequence analysis1 and X-ray analysis has yielded the atomic structure of the enzyme adenyl kinase2 (adenylate kinase, EC 2.7.4.3). No protein of which the structure is known is so closely related to adenyl kinase that an amino acid sequence comparison3 or an exact geometrical comparison of the structures4–6 can be expected to indicate a relationship. Similarities with other proteins become apparent, however, if one restricts the comparison to topologies, that is, to chain folds without reference to the exact geometry. Since chain folds are particularly well conserved during evolution7 such a procedure might reveal distant relationships.

A collagen-like amino acid sequence in a polypeptide chain of human C1q (a subcomponent of the first component of complement).

Abstract: 1. A partial amino acid sequence of 95 residues of the 191 residues in the oxidized A chain of human subcomponent C1q was determined. The partial nature of the sequence is because one overlapping peptide is missing in the proposed sequence, also the proof of some of the overlapping peptides depends partly on their amino acid composition and not on their complete sequence. 2. This region of the A chain contained a repeating sequence of glycine-X-Y (where X is often proline and Y is often hydroxyproline) for 78 residues. 3. The five hydroxylysine residues and the five hydroxyproline residues present in the oxidized A chain were all in these 78 residues and only in the Y position of the repeating sequence. 4. Prolonged collagenase digestion of the oxidized A chain yielded a large, apparently C-terminal, peptide which contained most of the non-collagenous sequences present in the chain. 5. It is concluded that there is a collagen-like region in the A chain of subcomponent C1q which constitutes most of the N-terminal half of the chain and that similar collagen-like regions will be found in the B and C chains.

The Amino‐Acid Sequence and Carbohydrate Content of Phospholipase A2 from Bee Venom

Abstract: The complete amino acid sequence of phospholipase A2 from the venom of the common European honey-bee (Apis mellifica) has been determined. The sequence of amino acid residues at the N-terminus was obtained by direct application of the Edman degradation technique and that at the C-terminus by digestion with carboxypeptidases A and B. Digestion of the reduced and carboxymethylated enzyme with trypsin yielded a completely soluble peptide mixture, all the components of which were isolated and their structures determined. Overlaps of the tryptic peptides were deduced from the structures of peptides isolated after digestion of the reduced and carboxymethylated enzyme with chymotrypsin and of the reduced and aminoethylated enzyme with a protease specific for cleavage at lysine residues. Two remaining ambiguities were resolved by peptides obtained from a digest of the reduced, carboxymethylated and maleylated enzyme with trypsin. The phospholipase A2 consists of a single chain of 128 amino acid residues and contains attached carbohydrate residues. The composition and point of attachment of the carbohydrate moiety have been established.

The Amino-Acid Sequence of the Amino-Terminal 37 Residues of Human Parathyroid Hormone

Abstract: The sequence of the amino-terminal 37 residues of human parathyroid hormone has been established. The hormone used in these studies was isolated in highly purified form from parathyroid adenomata and was subjected to automated degradation in a Beckman sequencer. A high-sensitivity sequencing procedure employing 35S-labeled phenylisothiocyanate of high specific activity as the coupling agent was used. The sequence obtained differs from that of bovine parathyroid hormone in three of the first 37 positions, and from that of porcine parathyroid hormone in two positions. A single human-specific residue was found (asparagine 16). The sequence obtained differs at three positions (22, 28, and 30) from the structure for human parathyroid hormone reported recently by Brewer et al. [(1972) Proc. Nat. Acad. Sci. USA 69, 3585-3588] and synthesized by Andreatta et al. [(1973) Helv. Chim. Acta, 56, 470-473] We have carefully reviewed our data, reported here in detail, on the sequence positions in dispute. We must conclude, on the basis of all available data, that the structure that we propose is the correct structure. The objective resolution of these discrepancies in structural analysis through further chemical and immunochemical studies is important, since synthesis of human parathyroid hormone, in which there is widespread interest for physiological and clinical studies, must be based on the correct sequence of the human hormone if the peptide is to be genuinely useful.