Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q07644 (polypeptide)
 72,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

L-Azetidine-2-carboxylic acid, the naturally occurring lower homologue of L-proline, is incorporated into hemoglobin S (sickle hemoglobin) in vitro. Sickle erythrocytes from patients with sickle cell anemia incubated with L-[3H] azetidine-2-carboxylate synthesized radiolabeled hemoglobin which when isolated from cell lysates, co-chromatographed with hemoglobin S on DEAE-cellulose columns. The alpha/beta ratio of azetidine carboxylate incorporation into the globin chains of sickle hemoglobin was 0.94, which is consistent with the presence of four proline residues in each polypeptide chain. Incorporation of azetidine carboxylate into hot trichloroacetic acid-insoluble material in sickle erythrocytes indicated that the homologue was present in the polypeptide backbone of the globin chains of sickle hemoglobin. Amino acid analysis of the hot trichloroacetic acid-insoluble material from sickle erythrocytes which had been incubated with radiolabeled azetidine carboxylate indicated that 75% of the radioactivity could be accounted for as intact homologue while 20% of the radioactivity co-chromatographed with alanine. These results suggest that azetidine carboxylate is incorporated unaltered into hemoglobin S in addition to being metabolized to alanine in sickle erythrocytes prior to incorporation into protein. The kinetics of thermal precipitation of hemoglobin S (oxygen ligand) into which radioactive azetidine carboxylate or radioactive proline had been incorporated in vitro is identical. This observation, together with the behavior of hemoglobin S and the globin chains from hemoglobin S containing azetidine carboxylate during ion-exchange chromatography, indicates that homologue replacement of prolyl residues does not significantly alter the overall charge or stability of the hemoglobin S tetramer. Azetidine carboxylate did not inhibit uptake of radiolabeled proline by sickle erythrocytes suggesting that the homologue does not adversely affect amino acid transport in these cells.
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PMID:Incorporation of L-azetidine-2-carboxylic acid into hemoglobin S in sickle erythrocytes in vitro. 97 36

A fragment containing the pyruvic acid residue is isolated from hymotryptic hydrolyzate of alpha-polypeptide chain of carboxymethylated histidine decarboxylase (HD) 14C-phenylhydrasone. The pyruvate residue is estimated to be bind with alpha-amino group of N-terminal phenylalanine in alpha-polypeptide chain. N-terminal alanine is found in HD alpha-polypeptide chain after its reductive amination. It makes possible to determine the estimation of N-terminal amino acid sequence in HD alpha-chain.
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PMID:[Localization of pyruvic acid in the histidine decarboxylase of Micrococcus sp. n]. 97 73

Human C5a was isolated from complement-activated serum and was characterized for protein and carbohydrate content. The purified C5a was judged to be homogeneous by both polyacrylamide gel electrophoresis and immunologic techniques. The polypeptide moiety of C5a contains 73 amino acid residues which represent a m.w. of 8,200. Analysis of the carbohydrate moiety in C5a indicated 4 moles of glucosamine, 3 to 4 moles os sialic acid, 4 moles of mannose and 2 moles of galactose. The total carbohydrate content in C5a, therefore, amounts to approximately 25% of the apparent m.w. of the anaphylatoxin molecule. The protein and carbohydrate portions of C5a together equal a m.w. of approximately 11,000 which is considerably less than the 15 to 16,000 indicated by physical measurements. Human C5a contains a COOH-terminal arginine which is essential for anaphylatoxin activity and a sequence of Gln-Leu-Gly-Arg-COOH at the COOH-terminus which compares favorably with that of human C3a (Gly-Leu-Ala-Arg-COOH). Additional similarities between the C3a and C5a molecules include length of the polypeptide chain, number of disulfide bonds and an absence of tryptophan residues. A major chemical difference does exist between these two human anaphylatoxins, namely that carbohydrate is associated with C5a but is absent in the C3a molecule. The partial NH2-terminal sequence of C5a was determined as NH2-Thr-Leu-Glx-Lys-Ile-Glx-Glx-Ile-Ala- and direct comparison with the known sequence of human C3a shows little homology.
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PMID:Partial characterization of human C5a anaphylatoxin. I. Chemical description of the carbohydrate and polypeptide prtions of human C5a. 100 96

The amino acid sequence of the parvalbumin II of the pike is reported. The protein has a molecular weight of 11 435. It consists of a single polypeptide chain of 107 amino acid residues with an acetyl group blocking the N-terminus and an alanine residue at the C-terminus. The molecule has been enzymically cleaved by trypsin, thermolysin and by the protease of the Staphylococcus aureus strain V8. Chemical cleavages make use of the CNBr reaction and of the sulfocyanoethylation method. The comparison of this amino acid sequence with that of the parvalbumin III of the pike indicates that these two homologous proteins belong respectively to two different subgroups derived from an early gene duplication of an ancestral gene at least prior to the differentiation of the Osteichthyes.
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PMID:The primary structure of the parvalbumin II of pike (Esox lucius). 100 32

The amino acid sequence of caprine CMP, the negatively charged C-terminal fragment released by chymosin (rennin EC 3.4.23.4) from goat K-casein at the initial stage of the milk-clotting process, has been investigated. The complete sequence has been determined by analysing chymotryptic and "thermolysin" fragments of the CMP. Caprine CMP contains 66 amino acid residues, 2 being phosphorylated. Asp2, Asn5, Thr11, Ser6, SerP2, Glu7, Gln2, Pro6, Ala9 Val5, Met1, Ile6, Lys3, His1, and the carbohydrate-free polypeptide chain has a molecular weight of 6,998 daltons. The occurrence in caprine CMP of an additional phosphate group, linked to serine 168 in the C-terminal region Thr-Ser168-Thr-Glu170-Val.OH of the polypeptide chain, has given support to the phosphorylation code for caseins that we postulated earlier [28, 27]. According to this hypothesis, a specific phosphoryl kinase may recognize an anionic phosphorylation site corresponding to the tripeptide sequence Thr/Ser-X-Glu, X being any amino acid residue. Since the C-terminal sequence of bovine and caprine CMPs differ by the substitution Ala/Glu170 (caprine), phosphorylation of caprine serine 168 could be explained by the occurrence of the new phosphorylation site Ser168-Thr-Glu170.
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PMID:[Primary structure of the casein macropeptide of caprine kappa casein]. 101 51

Serum contains a polypeptide with insulin-like activity not suppressible by insulin antibodies (NSILA). A large-scale isolation procedure for NSILA is described, starting from an acid ethanol extract of a Cohn fraction (precipitate B) obtained from human plasma. Two homogenous polypeptides with insulin-like and cell-growth promoting activities could be isolated by gel filtration, ion exchange chromatography, and preparative polyacrylamide gel electrophoresis. Both components are slightly basic polypeptides with a minimal molecular weight of 5800 +/- 400. Both are single-chain molecules with two intrachain disulfide bridges each and no free sulfhydryl groups. NSILA I and II differ, however, in their amino acid compositions. The N-terminal amino acid sequences are Gly-Pro-Glu- in NSILA I, and Ala-Tyr-Arg- and Tyr-Arg- in NSILA II. Both NSILA I and II enhance net gas exchange in adipose tissue with a specific activity 60 times lower than that of insulin. In the range of 1-50 ng/ml, both substances stimulate [3H]thymidine incorporation into DNA of chick embryo fibroblasts. The same effect can be obtained with insulin but only at concentrations 50-100 times higher than those of NSILA. These results suggest that NSILA I and II are two forms of an insulin-like hormone with predominating effects on cell and tissue growth parameters.
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PMID:Polypeptides with nonsuppressible insulin-like and cell-growth promoting activities in human serum: isolation, chemical characterization, and some biological properties of forms I and II. 106 87

Human fetal membranes contain two new genetically distinct collagen polypeptide chains which are subunits of one (or two) new molecular species of collagen. These new polypeptide chains, which we have tentatively named alphaA and alphaB, have been directly compared with the polypeptide chain subunits of Types I, II, and III human collagen and Type IV collagen from bovine lens capsule. Both alphaA and alphaB exhibit characteristic profiles on carboxymethyl-cellulose chromatography and sodium dodecyl sulfate/polyacrylamide gel electrophoresis. The distribution of methionine residues along both new chains is different from known collagen chains as manifest by distinctly different cyanogen bromide peptide profiles on carboxymethyl-cellulose chromatography and/or sodium dodecyl sulfate/polyacrylamide gel electrophoresis. Both alphaA and alphaB exhibit contents of amino acids and glycine typical of collagens, and comparison with the observed and reported compositions of collagen chains of Types I-IV collagens reveals notable differences, particularly in the content of alanine, leucine, isoleucine, and the basic amino acids, lysine, hydroxylysine, and arginine. The new collagen species containing both alphaA and alphaB may be separated in the native (triple-helical) state from other native collagen species by differential salt precipitation. The observations that both chains coprecipitate in the same narrow NaCl range, and that the ratio of alphaA:alphaB is constant, suggest the possibility of a single new species of collagen with a subunit structure alphaA [alphaB]2.
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PMID:Fetal membrane collagens: identification of two new collagen alpha chains. 106 66

In inbred rats, the antibody response to the known sequential polypeptide (Tyr-Glu-Ala-Gly)n (T-G-A-Gly)n is under the control of two independently assorting loci; (co) dominant, Ag-B-linked Ir-(T-G-A-Gly) I, controlling qualitative responsivenss, and a non-Ag-B-linked modifier locus termed Ir-(T-G-A-Gly) II, controlling the level of antibody produced. The antibody response to (T-G-A-Gly)n was solely IgG and the level of antibody produced was dependent upon Ir-(T-G-A-Gly) II for phenotypic response type.
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PMID:Genetic control of the immune response in rats to the known sequential polypeptide (Tyr-Glu-Ala-Gly)n. I. Antibody responses. 108 17

A glycanase activity, catalyzing the depolymerization of host capsular polysaccharide, is associated with Escherichia coli capsule bacteriophage no. 29, a small virus with an isometric head, carrying a base plate with a set of spikes. The bacteriophage particles were disrupted by mild acid treatment (5 to 8 min at pH 3.5 and 37 C), and the enzymatically active fragments were isolated and subjected to sodium dodecyl sulfate-gel electrophoresis as well as to electron microscopy. Of the at least nine different polypeptide chains found in the complete virion, three (of 57,000 plus or minus 3,000, 29,500 plus or minus 2,000 and 13,500 plus or minus 1,000 daltons) were detected in detached base plates. They had the appearance of six-pointed stars of about 14 nm in outer diameter, with a central hole or prop, carrying six (or, possibly, a multiple thereof) spikes. Two sizes of polypeptide chains (57,000 and 29,500) were found in pure spikes, cylindrical particles of about 14.5 to 15 nm in length and 5 nm in diameter, and one (57,000) in -- still capsule depolymerizing -- spike subunits of roughly 5 nm in diameter. Phage 29 spike preparations, homogeneous in analytical ultracentrifugation and immunoelectrophoresis, were found to have a molecular weight of 245,000, as determined from the sedimentation equilibrium, and to contain equimolar amounts of the two polypeptides, probably three copies of each per organelle. The amino acid analysis of the isolated spikes revealed that aspartic acid, alanine, serine, and glycine are their dominant constituents; no amino sugars or other carbohydrates were detected in the preparations.
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PMID:Escherichia coli capsule bacteriophages. III. Fragments of bacteriophage 29. 109 Jul 54

Intracistronic alpha-complementation between a cyanogen bromide digest of beta-galactosidase and an extract of the lac Zminus operator-proximal deletion mutant M15 was used to monitor the purification of a cyanogen bromide peptide (CB2) responsible for the complementation. Key steps in the purification were ion exchange chromatography on carboxymethylcellulose and sulfopropyl-Sephadex in the presence of urea, and Sephadex gel filtration. CB2 contains residues 3 to 92 of beta-galactosidase. Its sequence is: Ile-Thr-Asp-Ser-Leu-Ala-Val-Val-Leu-Gln-Arg-Arg-Asp-Trp-Glu-Asn-Pro-Gly-Val-Thr-Gln-Leu-Asn-Arg-Leu-Ala-Ala-His-Pro-Pro-Phe-Ala-Ser-Trp-Arg-Asn-Ser-Glu-Glu-Ala-Arg-Thr-Asp-Arg-Pro-Ser-Gln-Gln-Leu-Arg-Ser-Leu-Asn-Gly-Glu-Trp-Arg-Phe-Ala-Trp-Phe-Pro-Ala-Pro-Glu-Ala-Val-Pro-Glu-Ser-Trp-Leu-Glu-Cys-Asp-Leu-Pro-Glu-Ala-Asp-Thr-Val-Val-Val-Pro-Ser-Asn-Trp-Gln-Met. Thus no more than 1/13 of the beta-galactosidase polypeptide chain, starting 2 residues from the NH2 terminus, is necessary for alpha-complementation with M15 as alpha-acceptor.
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PMID:Amino acid sequence of beta-galactosidase. IV. Sequence of an alpha-complementing cyanogen bromide peptide, residues 3 to 92. 109 37


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