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)

After the cleavage of disulfide bonds of macroglobulin isolated from channel catfish (Ictalurus punctatus), an electrophoretically fast-moving polypeptide, which resembled human J chain, was released. On a Sephadex G-200 column equilibrated in 5 M guanidine, the elution position of the J chain overlapped with the descending part of the L chain peak. Further purification was achieved by DEAE ion-exchange chromatography. The isolated polypeptide, which had a molecular weight of 14,800 +/- 500, as determined ultracentrifugally by sedimentation equilibrium in 5 M guanidine, contained 7% carbohydrate with one residue of fucose, two of mannose, one of galactose, two of glucosamine, and one of sialic acid per chain. A comparison of catfish and human J chain amino acid analyses showed the former to have a higher content of serine, glycine, and phenylalanine and a lower content of aspartic acid, isoleucine, and arginine. Tryptic peptide maps of catfish and human J chains revealed very few common peptides. Rabbit and guinea pig antisera to human J chain did not cross-react with catfish J chain. Untreated, resuced and alkylated, S-sulfonated, or cyanogen bromide cleaved macroglobulin from the gar (Lepisosteus osseus) contained no polypeptide analogous to either catfish or human J chain by the criteria employed in this study.
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PMID:Identification and properties of J chain isolated from catfish macroglobulin. 80 10

Stratum corneum alpha protein, the principal structural protein of the epidermis, and its precursor prekeratin have been studied. Both proteins have similar patterns on sodium dodecyl sulfate electrophoresis and consist of several polypeptide chains (designated A, A', B, B'). These subunits have been isolated by chromatography on diethylaminoethyl cellulose in 8 M urea and characterized. Immunological studies have shown that the four subunits could be grouped into two distinct immunological groups referred to as the A and B groups and analysis of the cyanogen bromide fragments of purified components appeared to support such a hypothesis. X-ray diffraction studies have shown that at least one A component and one B component are necessary for the production of a typical alpha X-ray diffraction pattern. Circular dichroism studies have shown that the polypeptide chains of either class have low ellipticity when compared to the intact molecule, indicating that both chains are necessary for the formation of an alpha-helical structure.
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PMID:Isolation of the polypeptide chains of prekeratin. 81 Dec 64

Polypeptide fragments corresponding to the NH2-terminal 55 amino acids of betaS and betaA globins were prepared by cyanogen bromide treatment of globin and isolated by gel filtration on Sephadex G-50. Sheep were immunized with the isolated NH2-terminal fragments, and one of these sheep produced precipitating antibodies to the NH2-terminal fragment of betaS globin. These antibodies also reacted with betaA and betaS globin and hemoglobins A and S, as shown by immunodiffusion and quantitative precipitation studies. A radioimmunoassay was developed using the radioiodinated NH2-terminal fragment as tracer, and dextran-coated charcoal for separating bound and free peptide. The radioimmunoassay was used to characterize the interaction of the antibodies and the NH2-terminal fragment of betaS globin.
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PMID:Antibodies to an NH2-terminal fragment of betaS globin. I. Preparation and radioimmunoassay. 81 53

The purification procedure for mammalian glial fibrillary acidic protein allowed the isolation of related proteins from the brain and spinal cord of the chicken, turtle, frog and fish. With the exception of the turtle, the proteins so isolated were homogeneous and migrated as a single band on sodium dodecyl sulfate-acrylamide gel electrophoresis, displaying the same mobility as bovine glial fibrillary acidic protein, 54 000 mol. wt. In the turtle an additional slower migrating band was constantly present, together with the main species. Mammalian and submammalian proteins were similar in amino acid composition and appeared to be susceptible to the same type of in situ proteolysis, with degradation of the major species into multiple polypeptides ranging down to 40 500 mol. wt. Unless degraded, the proteins isolated from submammalian vertebrates were excluded from sodium dodecyl sulfate-acrylamide gels if a reducing agent was not added to the electrophoretic sample, thus suggesting the existance of disulfide bridges between polypeptide chains, as demonstrated for the mammalian protein. The purified submammalian antigens cross-reacted with antisera to human glial fibrillary acidic protein with formation of spurs not only at the junction between mammalian and submammalian precipitation lines, but also between submammalian lines. The antisera produced against chicken antigen did not react with the human antigen and the antichicken sera could not be absorbed with human antigen. An immunologically active cyanogen bromide peptide in the myoglobin range (17 200 mol. wt.) characteristic of the mammalian protein, degraded and nondegraded, was not present in the digest of the submammalian proteins.
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PMID:Isolation and initial characterization of glial fibrillary acidic protein from chicken, turtle, frog and fish central nervous systems. 82 71

Cleavage of bovine carbonic anhydrase CI by cyanogen bromide at the 3 methionine residues yields 4 fragments which were isolated by insolubilisation (IICNBr) and gel filtration on Sephadex G-50 in alkaline medium (ICNBr, IIICNBr, IVCNBr). Sequence studies performed on these fragments allowed the alignment of the 64 first residues (tryptic units T1 to T7) and the 89 last residues (tryptic units T19 to T26) of the polypeptide chain. From a tryptic hydrolysate of the maleylated protein arginylpeptides M1 to M10 have been isolated by gel filtration on Sephadex G-50 followed by purification of heterogeneous fractions. Investigations on M4 and M6 achieved the determination of the primary structure of the bovine carbonic anhydrase CI. Its comparison with the sequence of human B and C and ovine C erythrocyte carbonic anhydrases was discussed in connection with the actual data concerning the three-dimensional structure and the catalytic mechanism of the carbonic anhydrase isozymes.
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PMID:[Primary structure of bovine erythrocyte carbonic carbonic anhydrase CI. II. Complete sequence]. 82 82

Two aspects of the subunit structure of the bovine brain specific protein 14-3-2 have been examined. On the one hand, native 14-3-2 has been separated into two fractions by hydroxylapatite chromatography. One eluted at the same position when chromatographed on the same column, while the other redistributed into the same two fractions again. Amino acid analysis of these two forms of 14-3-2 gave results that were not significantly different under the condition of analysis. Furthermore, when each peak was subjected to cyanogen bromide cleavage, very similar elution profiles of the resultant fragments were obtained. The two pools also cross-reacted with antiserum to 14-3-2. Reaction of purified 14-3-2 with dimethylsuberimidate caused the formation of covalently bound protein units of 100,000 molecular weight when measured by sodium dodecyl sulfate polyacrylamide gel electrophoresis, as opposed to the 50,000 minimal molecular weight normally detected. On the other hand, analysis of the soluble tryptic peptides of S-[14C]carboxymethyl 14-3-2 yielded only three distinct radioactive peptides, each with one residue of S-carboxymethylcysteine whereas 8 are expected on the basis of the amino acid composition of the 50,000 molecular weight polypeptide chains. Thermolysin digestion of a similarly modified 14-3-2 preparation yielded all of the radioactivity in 5 S-carboxymethylcysteine-containing peptides. The partial amino acid sequence of these peptides indicates that they represent 4 unique areas of the polypeptide chain. Since 8 such peptides were expected, that is, double the number found, the minimum structural unit of the protein must be of 25,000 molecular weight. The results of these experiments do not permit distinction between a duplication of the structure within a single polypeptide chain or the alternate possibility of two polypeptide chains bound by unusually strong non-covalent bonds. These results suggest that 14-3-2 is a covalently linked dimer of 25,000 mol.wt. units that can aggregate to form larger species of 100,000 mol.wt. and higher.
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PMID:The subunit structure of bovine brain 14-3-2. 85 1

Vaccinia virus particles were dissociated into their constituent polypeptides and analysed by sodium dodecyl sulfate (SDS) gel electrophoresis. Thirty-three distinct polypeptide bands were identified and their molecular weights ranged between 11 000 and 150 000 daltons. Specific staining of gels containing polypeptides of dissociated virions revealed the presence of eight glycopeptides. No lipopeptides were detected. Analysis of chemical extracts (urea, guanidine hydrochloride, and alkali treatment) of the virus by SDS gel electrophoresis indicated that a total of 10 to 14 different polypeptides ranging in molecular weights from 11 000 to 70 000 daltons were solubilized. Analysis of detergent extracts and of the remains of extracted viral particles has shown that the detergent Nonidet P-40 (NP-40) solubilized a total of 11 polypeptides of which 6 were glycopeptides. The other detergents sodium deoxycholate (SDC) and cetyl trimethyl ammonium bromide (CTAB) were not as selective. both solubilizing more than 25 of the polypeptides composing the virus. Gel electrophoresis results also indicated that most of the small molecular weight (11 000-70 000 daltons) polypeptides were readily solubilized by NP-40, SDC, and CTAB, while those with molecular weights of 70 000 daltons and higher were not well solubilized. The effects of detergents were also analysed by electron microscopy. Evidence was obtained for subpopulations of viral particles having different susceptibility to detergent extraction.
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PMID:Effect of detergents and chemicals on purified vaccinia virus: analysis by SDS polyacrylamide gel electrophoresis and electron microscopy1,2. 85 21

Factor XII was purified approximately 14 000-fold from bovine plasma by ammonium sulfate fractionation followed by heparin-agarose, DEAE-Sephadex, CM-cellulose, arginine-agarose, and benzamidine-agarose column chromatography. By this method, about 15 mg of protein was purified from 15 L of plasma with an overall yield of 18%. The purified protein was homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and amino-terminal analysis. Bovine factor XII is a glycoprotein with a mol wt of 74 000 as determined by sedimentation equilibrium centrifugation. It contains 13.5% carbohydrate including 3.4% hexose, 4.7% N-acetylhexosamine, and 5.4% N-acetylneuraminic acid. Factor XII is a single polypeptide chain with an NH2-terminal sequence of Thr-Pro-Pro-Trp-Lys-Gly-Pro-?-Lys-His. This sequence is homologous to the reactive-site regions of a number of protease inhibitors. The amino acid sequence of a carboxyl-terminal fragments prepared by cyanogen bromide digestion was found to be Leu-Cys-Ala-Gly-Phe-Leu-Glu-Gly-Gly-Thr-Asp-Ala-Cys-Gln-Gly-Asp-SER-Gly-Gly-Pro-Leu-Val-Cys-Glu-Asp-Glu. This sequence is homologous with the active site of a number of plasma serine proteases including thrombin, factor IXa, factor Xa, and plasmin. These data indicate that bovine factor XII is a precursor to a serine enzyme with an inhibitor sequence and a catalytic site located in the same single polypeptide chain.
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PMID:Isolation and characterization of bovine factor XII (Hageman factor). 86 Dec 10

Cytokinin binding protein was isolated and purified from tobacco leaves by bioaffinity chromatography on a Sepharose column on which benzyladenine (BA), synthetic cytokinin, had been introduced as an affinity ligand by the cyanogen bromide method. The purified protein bound specifically to cytokinins; its binding was inhibited remarkably by the addition of BA and kinetin and slightly by adenine, but not by adenosine in vitro. The dissociation constant, Kd, of the protein-BA complex was about 4 x 10(-5)M. The profiles of SDS polyacrylamide gel electrophoresis and gel filtration indicate that the protein consisted of a single polypeptide chain. Amino acid analysis showed that the protein contained 4 basic, 6 acidic, and 25 neutral amino acids but lacked tryptophan. The molecular weight of the protein was determined to be about 4,000 to 5,000 daltons by gel filtration, SDS polyacrylamide gel electrophoresis and amino acid analysis. The coupling conditions of BA to Sepharose by the cyanogen bromide method are described and discussed.
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PMID:Isolation of cytokinin binding protein from tobacco leaves by bioaffinity chromatography and its partial characterization. 86 70

A phosphorylated polypeptide (E4) of molecular weight 5000-6000, has been isolated from bovine embryonic enamel by Bio-Gel P-10 gel filtration and DE-52 ion-exchange chromatography. The peptide contains three serine residues all of which are phosphorylated. All three O-phosphoserine residues are in glutamic acid-O-phosphoserine-tyrosine sequences that are distributed relatively evenly along the polypeptide chain. Although it was not possible to sequence the entire polypeptide chain directly by automatic peptide sequencing, a partial sequence and peptide map was constructed on the basis of the sequence and composition of peptides derived by cyanogen bromide, trypsin and chymotrypsin digestion. The presence of glutamic acid, tyrosine and leucine adjacent to and near the O-phosphoserine residues may be important in calcium binding and in mineralization.
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PMID:Isolation, characterization and partial amino acid sequence of a phosphorylated polypeptide (E4) from bovine embryonic dental enamel. 88 76


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