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)

During the isolation and purification of erythroid cell-stimulating factors from fetal tissues and blood, we found that they were almost invariably contaminated with substances that inhibited thymidine incorporation into erythroid cells of fetal bovine liver. We have isolated and partially sequenced three of these inhibitory factors. The first one was a 46-kDa heparin-binding protein from fetal bovine serum with 80% sequence identity with human apolipoprotein H (apo H). Although human apo H had no inhibitory activity on thymidine incorporation, the bovine apo H-like protein inhibited thymidine incorporation with an ID50 of 36 nM. It probably belongs to a group of heparin-binding apolipoproteins such as apo B and E, which have been reported to inhibit hematopoietic cells. The second inhibitor isolated from fetal bovine serum was clearly cytotoxic at a concentration of 1 nM. This 11-kDa peptide seems to be structurally related to the anaphylatoxins. The third inhibitor was isolated from human fetal intestine. The amino-terminal sequence of this protein was nearly identical to the amino-terminal sequence of human phospholipase A2 isolated from pancreas or lung. Bovine liver erythroid cell membranes are particularly sensitive to phospholipases. Since the synthesis and secretion of phospholipase A2 has been reported to be under the control of interleukin-1 or tumor necrosis factor in different cells, it is possible that this enzyme may be secreted locally and play an important role in tissue remodeling during injury or fetal development.
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PMID:Isolation and characterization of three inhibitors of thymidine incorporation into bovine fetal liver cells. 206 6

An 8 kd heparin-binding peptide which stimulates thymidine incorporation in cultures of fetal calf liver erythroid cells was isolated from fetal bovine serum by affinity chromatography on Heparin-Sepharose, ion exchange chromatography, gel filtration and reversed-phase HPLC. The N-terminal sequence of the isolated peptide was identical to the N-terminal sequence of bovine erythrotropin or insulin-like growth factor II (IGF II). The potential heparin-binding site of IGF II is probably situated in the arginine-rich C-peptide region. The affinities of human recombinant IGF I and II were compared with those of apolipoprotein H (a plasma heparin-binding protein) and bovine insulin in a heparin-affinity column. The retention times were in the order: Apolipoprotein H greater than hrIGF II greater than hrIGF I greater than insulin (no retention). This unusual property of IGF II suggests that it may be captured in the extracellular matrix in a similar way to fibroblast growth factor, interleukin 3 or granulocyte/macrophage colony-stimulating factor.
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PMID:A heparin-binding erythroid cell stimulating factor from fetal bovine serum has the N-terminal sequence of insulin-like growth factor II. 230 23

A 46 kDa heparin-binding protein which inhibits thymidine incorporation in cultures of fetal calf liver erythroid cells was isolated from fetal bovine serum by affinity chromatography on heparin-Sepharose, ion-exchange chromatography, gel filtration and reversed-phase h.p.l.c. The N-terminal sequence of the first 22 amino acids showed 81% identity with the published sequence of human apolipoprotein H. The isolated protein inhibited thymidine incorporation with an ED50 (concn. producing 50% of maximal effect) of 36 nM. A 100% inhibition of thymidine incorporation and a 40% decrease in cell numbers in cultures of fetal calf erythroid cells were observed at a protein concentration of 840 nM. No effects could be seen in cultures of 3T3 cells used as controls. Human apolipoprotein H had no inhibitory activity in any of the cell cultures tested, suggesting a species-specificity or a different structure or function for the bovine heparin-binding protein.
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PMID:Isolation from fetal bovine serum of an apolipoprotein-H-like protein which inhibits thymidine incorporation in fetal calf erythroid cells. 232 84