Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02749 (beta2-glycoprotein I)
 836 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

DNA-binding proteins were isolated from Yoshida ascites tumor fluid by chromatography on DNA-cellulose. This fraction represents 1-2% of the total ascites protein. Most of the DNA-binding proteins will bind to phosphocellulose as well. The proteins migrate by agarose gel electrophoresis at pH 8.6 as alpha and beta globulins. Quantitative immunoelectrophoresis revealed the presence of 12-18 proteins. SDS-polyacrylamide electrophoresis indicated molecular weights ranging from 3-10(4) to 10(6). Seven of the proteins were identified by specific immunoprecipitation as beta1-Eglobulin, beta2-glycoprotein I, fibrinogen split product E (fibrinogen E), coagulation factor XIII (factor XIII), alpha2-macroglobulin, IgG and IgM. Alpha1-antichymotrypsin might also be represented. In nuclear extracts of the tumor cells only factor XIII was present. With the exception of fibrinogen E and P5 all recognized DNA-binding proteins are present in normal rat plasma. With increasing tumor age the concentration of fibrinogen E, factor XIII, P5 and IgM increased both in ascites fluid and in plasma, while the concentration of other DNA-binding-proteins decreased or remained constant. Evidence is presented that the DNA- and phosphocellulose binding ascites protein fraction inhibit tumor cell growth. No inhibition was induced by corresponding protein fractions isolated from normal rat plasma.
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PMID:DNA-binding proteins in Yoshida ascites tumor fluid. 95 99

The horseshoe crab clotting factor, factor C, present in the hemocytes is a serine-protease zymogen activated with lipopolysaccharide. It is a two-chain glycoprotein (Mr = 123,000) composed of a heavy chain (Mr = 80,000) and a light chain (Mr = 43,000) [T. Nakamura et al. (1986) Eur. J. Biochem. 154, 511-521]. In our continued study of this zymogen, we have now also found a single-chain form of factor C (Mr = 123,000) in the hemocyte lysate. The heavy chain had the NH2-terminal sequence of Ser-Gly-Val-Asp-, consistent with that of the single-chain factor C, indicating that the heavy chain is derived from the NH2-terminal part of the molecule. The light chain had an NH2-terminal sequence of Ser-Ser-Gln-Pro-. Incubation of the two-chain zymogen with lipopolysaccharide resulted in the cleavage of a Phe-Ile bond between residues 72 and 73 of the light chain. Concomitant with this cleavage, the A (72 amino acid residues) and B chains derived from the light chain were formed. The complete amino acid sequence of the A chain was determined by automated Edman degradation. The A chain contained a typical segment which is similar in sequence to a family of repeats in human beta 2-glycoprotein I, complement factors B, protein H, C4b-binding protein, and coagulation factor XIII b subunit. The NH2-terminal sequence of the B chain was Ile-Trp-Asn-Gly-. This chain contained the serine-active site sequence-Asp-Ala-Cys-Ser-Gly-Asp-Ser-Gly-Gly-Pro-. These results indicate that horseshoe crab factor C exists in the hemocytes in a single-chain zymogen form and is converted to an active serine protease by hydrolysis of a specific Phe-Ile peptide bond.
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PMID:Lipopolysaccharide-sensitive serine-protease zymogen (factor C) of horseshoe crab hemocytes. Identification and alignment of proteolytic fragments produced during the activation show that it is a novel type of serine protease. 330 57