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)

The articular lubricating fraction from bovine synovial fluid was prepared by repeated fractionation in three consecutive CsCl density gradients to remove completely traces of hyaluronic acid. The major glycoprotein consituent (LGP-I) was then isolated by repeated gel-permeation chromatography. The yield of the LGP-I component was about 20 mg/litre of synovial fluid. Sedimentation-equilibrium measurements showed that this glycoprotein was homogeneous and the mol.wt. was calculated to be 227500. Amino acids represented 43% (w/w) and carbohydrate constituents 44% (w/w) of the molecule. Threonine, glutamic acid, proline and lysine (224, 127, 242 and 128 residues/1000 residues respectively) were the major amino acids. Galactosamine, galactose and N-acetylneuraminic acid (202, 162 and 114 residues/molecule of LGP-I component respectively) accounted for 98% of the total carbohydrate residues present. Small amounts of mannose and glucosamine (1 and 9mol respectively/mol of LGP-I component) were also present. After treatment of LGP-I component with alkali and NaB3H4 radioactivity was incorporated into alpha-aminobutyric acid and alanine in a molar ratio of 4:1, and radioactive galactosaminitol was isolated by ion-exchange chromatography from a cleaved oligosaccharide fraction. These data demonstrate the presence of threonine and serine -O-GalNAc linkages, but only 25% of the theoretical likages involving threonine were cleaved by a beta-elimination reaction. Digestion of LGP-I component with Pronase followed by chromatography on DEAE-cellulose yielded glycopeptide fractions with a similar amino acid and carbohydrate composition to the intact molecule. Treatment of desialylated and intact LGP-I component with galactose oxidase followed by reduction with NaB3H4 revealed the presence of 52mol of terminal galactose in the intact molecule and 153mol of galactose/mol of LGP-I component after treatment with neuraminidase. The data indicate the LGP-I component is composed of a single polypeptide chain containg more than 150 oligaosaccharide side chains composed of O-GaINAc-Gal distributed over the length of the peptide chain and that terminal sialic acid residues are linked to galactose in two-thirds of these side chains.
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PMID:The isolation and partial characterization of the major glycoprotein (LGP-I) from the articular lubricating fraction from bovine synovial fluid. 1 48

Thirteen strains of human influenza virus producing in chick embryo cell (CEC) cultures either virions with low infectivity or no virions were studied. In CEC, most of the strains induced synthesis of viral RNA, polypeptides, and ribonucleoprotein and produced functionaly active haemagglutinin, neuraminidase and virions lower infectivity. The low infectivity of virions produced by strains of this functional group was due to disturbed cleavage of a polypeptide, haemagglutinin precursor, formed in CEC, into a heavy a light haemagglutinin chain. Two strains belonging to another functional group induced no synthesis of virus-specific macromolecules in CEC, but were able to adsorb onto the cells. With one of these viruses, no transcription of parental RNA could be detected in CEC. There was no relationship between the grouping of the studied strains into a certain functional group with their antigenic characteristics, the year of isolation, the passage history in chick embryos and human pathogenicity.
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PMID:Investigation on the mechanisms of the failure of human influenza virus to replicate in chick embryo cell cultures. 2 Jul 62

Pathogenic mycoplasmas adhere to and colonize the epithelial lining of the respiratory and genital tracts of infected animals. An experimental system suitable for the quantitative study of mycoplasma adherence has been developed by us. The system consists of human erythrocytes (RBC) and the avian pathogen Mycoplasma gallisepticum, in which membrane lipids were labeled. The amount of mycoplasma cells attached to the RBC, which was determined according to radioactivity measurements, decreased on increasing the pH or ionic strength of the attachment mixture. Attachment followed first-order kinetics and depended on temperature. The mycoplasma cell population remaining in the supernatant fluid after exposure to RBC showed a much poorer ability to attach to RBC during a second attachment test, indicating an unequal distribution of binding sites among cells within a given population. The gradual removal of sialic acid residues from the RBC by neuraminidase was accompanied by a decrease in mycoplasma attachment. Isolated glycophorin, the RBC membrane glycoprotein carrying almost all the sialic acid moieties of the RBC, inhibited M. gallisepticum attachment, whereas asialoglycophorin and sialic acid itself were very poor inhibitors of attachment. Only part of the (125)I-labeled glycophorin bound to mycoplasmas could be removed by neuraminidase or by exchange with unlabeled glycophorin. It is suggested that glycophorin, representing the isolated major RBC receptor for M. gallisepticum, binds to the mycoplasmas both specifically, through its sialic acid moieties, and nonspecifically, through its exposed hydrophobic polypeptide moiety.
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PMID:Adherence of Mycoplasma gallisepticum to human erythrocytes. 2 7

Influenza PR8 particles resulting from strong treatment with caseinase C are spikeless, devoid of neuraminidase and hemagglutinin 1 and 2 glycopeptides, and contain a Schiff-negative polypeptide of about 13,000 molecular weight which exists as traces in intact virions. Their M-protein polypeptide content is reduced to 50% of its original value, but there is no evidence of particle disruption nor of lipid release. They fix complement in the presence of both anti-M-protein antiserum and antiserum raised against a host polysaccharide. During exposure to caseinase C, an antigen is unmasked. It is type-specific and its identity with the M-protein is discussed.
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PMID:Impairment of the M-protein and unmasking of a superficial type-specific antigen by proteolytic treatment of influenza A virions with preservation of host-specific antigenicity. 6 30

The method of electrophoresis in a single polyacrylamide gel plate was used for comparative study on virion polypeptides mobility in human influenza A and B virus strains. Molecular masses of individual polypeptides and their portion in the virion were determined. No variations in the migration speed of nucleoprotein (NP) and membrane protein (MP) were found in strains belonging to the same genus, but there were differences in the migration speed of these proteins in the genus A and genus B. Significant differences in migration and the content of glycoproteins, particularly of the heavy chain of hemagglutinin (HAI) in the genus A strain having different subtypes of hemagglutinin, including strains A/WS/33 (HONI), A/FM/1/47 (HINI), A/Sing/1/57 (H2N2), A/Port Chalmers/73 (H3N2), as well as in the genus B in strains B/Lee/40, B/Yamagata/1/73, and B/Johanesbourg/56. No differences in the mobility of glycoproteins in strains similar in the antigenic specificity of hemagglutinin and neuraminidase were found. On the basis of the comparative analysis of virion polypeptide electrophoregrams, three new strains on influenza A virus isolated in December, 1977, were identified as belonging to the species A (HINI).
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PMID:[Electrophoretic mobility of polypeptides in different strains on human influenza A and B viruses]. 8 Aug 85

Our knowledge of antigens which are associated with different types of malignant tumours is steadily increasing. These antigens exist in considerable numbers, but, so far with few exceptions, only their presence can be demonstrated by certain methods; to isolate and identify them has not yet been possible. These antigens are, therefore, suitable not so much for the primary diagnosis, but rather, like the carcinoembryonic antigen, the tissue-polypeptide antigen or the alpha-feto-protein, for assessing the success of treatment. Active immunization has recently received a fresh impulse by the use of the enzyme neuraminidase, derived from Vibrio cholerae, in the treatment of tumour cells. There is no passive specific immunotherapy in human cancer. As to specific active immunotherapy BCG, Corynebacterium parvum and preparations of these and other micro-organisms together with polynucleotides, levamisol, statolon, tilorone have been employed. Although the results are not uniform they are promising. Attempts at cellular transfer of immunity are not very encouraging. It should be emphasized that the findings apply to human cancer. Experimental studies have produced very interesting results.
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PMID:[Immunotherapy of malignant growths (author's transl)]. 8 28

Representative isolates of the paramyxoviruses duck/Hong Kong/75 and duck/Mississippi/75 were shown to be serologically closely related by haemagglutination and neuraminidase inhibition tests. The structural polypeptides of these viruses were also shown to be similar. For each of the isolates tested, polyacrylamide gel electrophoresis in the presence of SDS revealed a similar polypeptide pattern consisting, under reducing conditions, of seven polypeptides with apparent mol. wt. ranging from 46000 to 190000. Each virus had two glycosylated polypeptides with apparent mol. wt. of 56000 and 71000 to 72000 under reducing conditions and 62000 to 63000 and 135000 to 142000 under non-reducing conditions.
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PMID:Antigenic and structural relationships between avian paramyxoviruses isolated from ducks in Hong Kong and Mississippi, U.S.A. 9 19

Thyroxine-binding globulin (TBG), prepared from human serum by an improved purification method, was treated with a mixture of neuraminidase, beta-galactosidase, alpha-mannosidase, and beta-N-aectylglucosaminidase, which resulted in the removal of approximately 86% of saccharides. Purification by thyroxine-Sepharose affinity chromatography gave a homogeneous protein as shown by equilibrium sedimentation and sodium dodecylsulfate-polyacrylamide gel electrophoresis. Amino acid and NH2-terminal sequence analysis indicated that the protein moiety was intact. Deglycosylation had no effect on the stoichiometry of the binding of L-thyroxine as shown by tryptophanyl fluorescence quenching and equilibrium dialysis at pH 8.6 and 25 degrees C. However, the affinity constant for L-thyroxine was reduced from 1.6 X 10(9) M-1 to 0.58 X 10(9) M-1. Analysis of radioimmunoassay data revealed that deglycosylation resulted in a slight decrease of the affinity constant for anti-TBG antibody from 3.9 X 10(10) M-1 to 1.8 X 10(10) M-1. These results suggest that the polypeptide moiety, rather than the heterosaccharides, contains the antigenic determinants. Removal of the majority of the heterosaccharides of TBG has only a minor effect on its immunoreactivity and on the binding of thyroid hormone.
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PMID:Effect of deglycosylation on the binding and immunoreactivity of human thyroxine-binding globulin. 11 1

The function and several of the structural features of the C1 inactivator protein isolated from the plasma of a mother and daughter with the variant form of hereditary angioneurotic edema have been examined. These abnormal inhibitors shared immunologic identity with the normal C1 inactivator protein; however, they were inactive in inhibiting the functional activity of C1s. Analysis of the abnormal inhibitors by sodium dodecyl sulfate (SDS) acrylamide gel electrophoresis suggested that each consisted of a single polypeptide chain, the mobility of which was slower than that of the normal C1 inactivator. The apparent molecular weight of the patients' inhibitors was 109,000 daltons as contrasted to 105,000 daltons, that of the normal C1 inactivator. The abnormal inhibitors failed to form a complex with C1s or plasmin as analyzed by SDS-acrylamide gels. The large proteolytic derivatives resulting from the plasmin- and trypsin-induced degradation of the abnormal inhibitors were approximately 3,000 daltons heavier than the corresponding products derived from normal C1 inactivator. Thus, the structural abnormality identified appeared to be a property of the core molecule. Treatment of the inhibitors with neuraminidase failed to demonstrate a difference between the normal and patient-derived C1 inactivator molecule. Neither were major differences found between the amino acid composition of the defective and normal inhibitors; however, the acidic amino acids tended to be higher in the patients' inhibitors, and the phenylalanine content lower. Thus, these studies have identified both structural and functional abnormalities in the C1 inactivator protein isolated from two related patients with hereditary angioneurotic edema. Examination of the interaction between endopeptidases and the inhibitors has further delineated the abnormal structural features.
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PMID:Studies on human plasma C1 inactivator-enzyme interactions. II. Structural features of an abnormal C1 inactivator from a kindred with hereditary angioneurotic edema. 12 52

The infectious virus (HVJ-pi) obtained from BHK cells persistently infected with haemagglutinating virus of Japan was found to be temperature-sensitive as well as causing little or no cytopathic effect (c.p.e.) and leading to establishment of carrier cultures in several cell lines at both permissive (32 degrees C) and non-permissive (38 degrees C) temperature. In order to obtain information about the role of HVJ-pi in the establishment of persistent infection, comparative studies were made of some phenotypic properties of HVJ-pi and HVJ-38 which was obtained by passing wild-type HVJ in eggs at 38 degrees C and was proved to be highly cytopathic. HVJ-pi differed from HVJ-38 in (1) temperature sensitivity in its ability to produce virus progeny, (2) infectivity for embryonated eggs, (3) neuraminidase activity, (4) the thermal stability of HA and neuraminidase activity, and (5) the polypeptide composition of BHK-grown viruses. B cells infected with HVJ-pi release haemagglutinin more efficiently, and less HA was accumulated on the cell membrane. In considering these results, it was concluded that the difference of envelope proteins might be involved in the striking difference in c.p.e. between HJV-pi and HVJ-38.
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PMID:Relationship between establishment of persistent infection of haemagglutinating virus of Japan and the properties of the virus. 18 15


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