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)

Vaccinia virus cores contain an activity which is able to relax both left-and right-handed superhelical DNA. This virus-specific nicking closing enzyme has been highly purified and differs from the corresponding host enzyme in salt optimum, in sedimentation coefficient, and in polypeptide composition as determined on sodium dodecyl sulfate/polyacrylamide gels. The enzyme is probably newly synthesized after the cessation of host protein synthesis which follows virus infection. The most highly purified preparation contains two polypeptides, one of molecular weight 24,000 and the other 35,000. The former polypeptide is a major constituent of the virus (7% of total protein by weight), whereas the latter is present in a much smaller amount (0.2%). Chromatography with denatured DNA-cellulose reveals that the activity is predominately associated with those fractions enriched in the polypeptide of greater molecular weight.
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PMID:A DNA nicking-closing enzyme encapsidated in vaccinia virus: partial purification and properties. 1 15

Secretory IgA is the prevailung immunoglobulin on the mucous membranes of different tissues. It is a polymer immunoglobulin and in comparison to the serum IgA the secretory IgA has a additional polypeptide chain, the secretory component. The secretory IgA is synthesized locally in the mucosa. Secretory IgA is a very important factor in the immune defence of the mucous membranes. Secretory antibodies are regulated independently from serum antibodies. They show a virus neutralizing effect and activities against bacteria and lifeless noxa. The mechanism is not yet clear. It is possible, that the reaction of the secretory IgA with the antigen prevents settlement of microorganisms on the mucous membranes. The clinical importance of secretory IgA is undoubted especially the deference of the mucosa in cases of a virus infection.
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PMID:[Secretory immunoglobulin A]. 14 11

In addition to the four major polypeptides VP1 and VP4, foot-and-mouth disease virus particles contain two minor polypeptides, mol. wt. 40 X 10(3) (P40) and 52 X 10(3) (P52). Extensive purification procedures failed to remove these minor polypeptides from the virus particles. Polypeptide P40 co-electrophoresed in SDS-polyacrylamide gels with VP0, the probable precursor of VP2 and VP4 and was inaccessible to iodination in situ. The second minor polypeptide, P52, co-electrophoresed with the virus infection associated (VIA) antigen found in large amounts in harvests of the virus grown in BHK 21 cells. Polypeptide P52 was shown to be located near the surface of the virus particle by iodination experiments and by its removal on incubating the particles with trypsin or chymotrypsin. Pactamycin mapping showed that this polypeptide was not a precursor of the structural polypeptides. About one copy of P52 and 4 copies of P40 were found in the virus particles sedimenting at 146S. However a larger number of copies was found in those virus particles sedimenting faster than the 146S peak.
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PMID:Characterization of the minor polypeptides in the foot-and-mouth disease particle. 17 28

Four primary cleavage products, mol. wt. 10(3) X 100, 88, 56 and 52 (P100, P85, P56 and P52 respectively) are present in BHK 2I cells infected with foot-and-mouth disease virus (FMDV). However, no precursor polyprotein equal to the sum of their mol. wt. was detected, even when amino acid analogues and proteolytic enzyme inhibitors were used. Three of the primary products were shown to cleave to smaller polypeptides, including the capsid polypeptides of the virus. Polypeptide P88, which was shown to be the precursor of the capsid polypeptides, is translated from the gene located at the 5'-end of the genome. The order of the structural polypeptides, determined by the use of emetine, is VP4, VP2, VP3, VP1. The order of the remaining primary cleavage products is P52, P56 and P100. P56 is a stable product, identical with the virus infection associated (VIA) antigen found in virus harvests. The function of the other two products P52 and P100 is not known. EMDV thus differs from other picornaviruses in that there is an extra primary cleavage product, apparently resulting from translation of more of the virus genome.
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PMID:Biochemical mapping of the foot-and-mouth disease virus genome. 19 8

mRNA extracted from a variety of simian virus 40 (SV40)-infected monkey cell lines directs the cell-free synthesis of viral T-antigen polypeptides with molecular weights estimated as 90,000 and 17,000. However, the size, abundance, and distribution of these T-antigens synthesized in vivo vary greatly over a range of permissive and transformed cell lines. To establish whether differences in the size of T-antigen polypeptides can be correlated with the transformed or lytic state, recently developed lines of SV40-transformed monkey cells that are permissive to lytic superinfection were analyzed for T-antigen. In these cells, regardless of the state of viral infection, the size and pattern of T-antigen are the same. However, species differences in the largest size of T-antigen are the same. However, species differences in the largest size of T-antigen do exist. In addition to the 90,000 T-antigen, mouse SV3T3 cells contain a 94,000 T-antigen polypeptide as well. Unlike the size variations in monkey cells, which are due to modification of T-antigen polypeptides, the 94,000 SV3T3 T-antigen results from an altered mRNA, since the cell-free products of SV3T3 mRNA also contains the 94,000 T-antigen polypeptide.
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PMID:Cellular and cell-free synthesis of simian virus 40 T-antigens in permissive and transformed cells. 20 21

In order to understand the functions of simian virus 40 genes, permissive cells (TC7) were infected with mutants temperature sensitive in the complementation groups A, B, C, BC, and D at permissive and nonpermissive temperatures. Cells were examined for the localization of viral polypeptide antigens by immunofluorescent staining with monospecific antibodies. The results are as follows: (i) The appearance of Vp1 antigen in cells infected by tsB, C, or BC mutants was not affected appreciably by the mutations. (ii) The appearance of Vp3 antigen was affected by the mutations in B, C, or BC. Vp3 antigen is confined to the nuclei in cells infected by wild-type virus. With mutant virus infection, Vp3 antigen is found in the cytoplasm, perinuclear region, and nucleoli. (iii) The tsD mutants and the tsA mutants did not express either Vp1 or Vp3 antigens at the nonpermissive temperature. (iv) Nucleoli seem to play an essential role in the biosynthesis and assembly of viral polypeptides. Thus, mutations in any one of complementation groups B, C, or BC, which are within the structural gene for Vp1, cause an alteration of intracellular distribution of another late gene product, Vp3. These results suggest that the amino acid sequences of Vp1 polypeptide play a role(s) in the transport of viral antigens across internal membranes or in virus assembly processes or in both.
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PMID:Vp1 affects intracellular localization of Vp3 polypeptide during simian virus 40 infection. 22 60

Plasma membranes isolated from normal and RSV transformed chick embryo fibroblasts were phosphorylated in vitro using endogenous protein kinase and ATP (gamma32P) and the labeled phosphoproteins were analyzed by SDS-PAGE. A number of protein phosphorylation changes were observed following transformation, however in most cases they were relatively small quantitative differences. The four major changes were in proteins of 47,000, 58,000, 75,000 and 135,000 daltons. Decreased phosphorylation of the 47,000 dalton polypeptide was found in transformed cell membranes but this alteration was shown to be due to differences in cell growth rather than transformation. Increase phosphorylation of the 75,000 dalton protein was at least partially related to virus infection. However, increased phosphorylation of the 58,000 and 135,000 dalton polypeptides were entirely transformation specific.
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PMID:Plasma membrane phosphoproteins in normal and Rous sarcoma virus transformed chick embryo fibroblasts: characterization by in vitro phosphorylation. 22 69

Determination of the amino acid sequence of the immunogenic polypeptides of hepatitis B surface antigen may not only permit molecular localization of the distinct determinants a, d, and y but may also lead to the synthesis of a hapten useful in prophylactic immunization against hepatitis B virus infection. For this purpose, purified monotypic hepatitis B surface antigen of adw subtype was resolved into equal amounts of two major polypeptides (22,000 and 28,000 daltons) and up to six other minor polypeptides by polyacrylamide gel electrophoresis. With the periodate staining reaction, only the 28,000-dalton polypeptide stained as a glycoprotein. Guinea pigs immunized with the 22,000-dalton polypeptide produced potent antisera against determinants a and d, but the 28,000-dalton glycoprotein did not induce a response. Both polypeptides isolated by preparative polyacrylamide gel electrophoresis showed amino acid composition identical with that of the intact antigen. For both polypeptides, hydrazinolysis gave Ile as the carboxyterminus, and carboxypeptidase A digestion gave the same terminal sequence, Val-Tyr-Ile. Both peptides also yielded an identical sequence of amino acids in nine steps of Edman degradation--Met-Glu-Asn-Ile-Thr-Ser(Cys)-Gly-Phe-Leu. Our data suggest that hepatitis B surface antigen contains a single major immunogenic 22,000-dalton polypeptide component, part of which is modified by the addition of carbohydrate to give rise to the glycopeptide of apparent molecular weight 28,000.
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PMID:Partial amino acid sequence of two major component polypeptides of hepatitis B surface antigen. 26 93

Seven differences in the polypeptide species of parental Syrian hamster embryo cells and cells of the highly tumorigenic derivative cell line BP6T were identified previously by employing the technique of two-dimensional polyacrylamide gel electrophoresis (Leavitt, J. and Moyzis, R. (1978) J. Biol. Chem. 253, 2497-2500). To determine which of these polypeptide changes are correlated with expression of the neoplastic state this work was extended to the comparative examination of nine established neoplastic cell lines which resulted from independent transformation events catalyzed by chemical carcinogen treatment, virus infection, or an unknown spontaneous event. Although no perfect correlation with a specific polypeptide change was found, two polypeptide changes, occurring independently or simultaneously, appear to be consistently associated with expression of neoplasticity. One polypeptide species, designated tau, having an isoelectric point of 4.6 and a molecular weight of 60 000 was lost or physically altered in all but one of these transformed cell lines; a second polypeptide species designated nu having an isoelectric point 5.5 and a molecular weight of 42 000 appeared in highly tumorigenic chemically transformed cell lines and in two virally transformed cell lines. A butyric acid supplement, used as a selective agent for butyric acid resistant cells, was employed to identify and isolate in a single step nascent neoplastic clonal lines transformed by ethylmethanesulfonate. These cell lines exhibited alterations either in tau or nu. The changes observed in tau are consistent with those expected to result from a somatic mutation event in the structural gene coding for tau; however, the alterations in tau could also be governed by a post-translational process. These findings suggest that alterations in expression of at least two major polypeptide species, tau and nu, are closely associated with primary steps in the neoplastic transformation process of Syrian hamster cells irrespective of the nature of the transforming agent.
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PMID:Two polypeptide changes associated with butyric acid resistance and the neoplastic state of Syrian hamster cells. 49 11

Purified full and empty virions of minute virus of mice were separated on CsCl gradients, and their polypeptides were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The empty particle contains two polypeptides, A (83,300 daltons) and B (64,300 daltons), which are 15 to 18% and 82 to 85%, respectively, of the virion mass. The full particle contains the single-stranded DNA genome, proteins A and B, and a third polypeptide, C (61,400 daltons). Again A is 15 to 18% of the protein mass, but the amounts of B and C vary inversely in different preparations of full particles. These polypeptides comprise greater than 99.6% of the protein in either virion, and their molecular weights and molar ratios are independent of the species of host cell on which the virus is propagated, They are not found in uninfected cells, and no protein component of uninfected cells copurifies with either virion under our conditions. Pulse-chase experiments show that the three proteins are synthesized only after virus infection and are therefore probably virus coded. Sequential harvesting from the nuclei of cells infected under one cycle growth conditions shows an increase in the proportion of C in full particles as infection progresses, suggesting that C is derived from B in a late maturation step.
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PMID:Three structural polypeptides coded for by minite virus of mice, a parvovirus. 98 92


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