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

cDNAs encoding the complement decay-accelerating factor (DAF) were isolated from HeLa and differentiated HL-60 lambda gt cDNA libraries by screening with a codon preference oligonucleotide corresponding to DAF NH2-terminal amino acids 3-14. The composite cDNA sequence showed a 347-amino acid protein preceded by an NH2-terminal leader peptide sequence. The translated sequence beginning at the DAF NH2 terminus encodes four contiguous approximately equal to 61-amino acid long repetitive units of internal homology. The repetitive regions contain four conserved cysteines, one proline, one glycine, one glycine/alanine, four leucines/isoleucines/valines, one serine, three tyrosines/phenylalanines, and one tryptophan and show striking homology to similar regions previously identified in factor B, C2, C4 binding protein, factor H, C1r, factor XIII, interleukin 2 receptor, and serum beta 2-glycoprotein I. The consensus repeats are attached to a 70-amino acid long segment rich in serine and threonine (potential O-glycosylation sites), which is in turn followed by a stretch of hydrophobic amino acids. RNA blot analysis of HeLa and HL-60 RNA revealed three DAF mRNA species of 3.1, 2.7, and 2.0 kilobases. The results indicate that portions of the DAF gene may have evolved from a DNA element common to the above proteins, that DAF cDNA predicts a COOH-terminal anchoring polypeptide, and that distinct species of DAF message are elaborated in cells.
 ...
PMID:Cloning and characterization of cDNAs encoding the complete sequence of decay-accelerating factor of human complement. 243 22

The plasma antithrombotic enzyme activated protein C (APC) has two major plasma inhibitors. One is heparin-dependent, has been characterized, and is known as protein C inhibitor. The second inhibitor was isolated based on its heparin-independent ability to inhibit and complex with APC. The purified inhibitor had the amino acid composition and NH2 terminus of alpha 1-antitrypsin and reacted with monoclonal antibodies to alpha 1-antitrypsin. The inhibitor was greater than 95% pure alpha 1-antitrypsin as judged by electroimmunoassay, inactivation of trypsin, and electrophoresis in two gel systems. To identify the second major plasma inhibitor of APC, immunoblot studies of enzyme-inhibitor complexes were made to compare APC addition to normal plasma and to plasma deficient in protein C inhibitor or alpha 1-antitrypsin. The results showed that alpha 1-antitrypsin is the second major plasma APC inhibitor. Given the association rate constant of alpha 1-antitrypsin for APC of 10 M-1 s-1 and its plasma concentration of approximately 40 microM, it accounts for approximately half of the heparin-independent APC inhibitory activity of plasma. Based on immunoblot analysis plasmas of 15 patients with intravascular coagulation contained APC-alpha 1-antitrypsin complexes suggesting that this inhibition reaction occurs in vivo. Thus, alpha 1-antitrypsin is a major physiologic inhibitor of APC.
 ...
PMID:Physiologic inhibition of human activated protein C by alpha 1-antitrypsin. 326 Dec 94

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.
 ...
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