Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1389183 (autodigestion)
 317 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasmin is a labile enzyme destroyed by a process termed autodigestion. Studied by a kinetic assay on the substrate Tos-Gly-Pro-Lys-pNA this process is shown to follow a bimolecular mode of reaction, which is retarded by plasmin degradation products. Plasmin is protected by fibrinogen, by epsilon-aminocaproic acid (6-aminohexanoic acid), by increasing ionic strength, and by glycerol. CNBr fragments of fibrinogen did not protect. Lack of substrate protection of plasmin may give rise to errors in a two-stage plasminogen activator assay, while the presence of substrate in a one-stage method prevents degradation of the generated plasmin.
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PMID:The autodigestion of human plasmin follows a bimolecular mode of reaction subject to product inhibition. 293 86

Plasmin, a broad spectrum proteinase, is inactivated by an autoproteolytic reaction that results in the destruction of the heavy and light chains of the protein. Recently we demonstrated that a 61-kDa plasmin fragment was one of the major products of this autoproteolytic reaction (Fitzpatrick, S. L., Kassam, G., Choi, K. S., Kang, H. M., Fogg, D. K., and Waisman, D. M. (2000)Biochemistry 39, 1021-1028). In the present communication we have identified the 61-kDa plasmin fragment as a novel four kringle-containing protein consisting of the amino acid sequence Lys(78)-Lys(468). To avoid confusion with the plasmin(ogen) fragment, angiostatin(R) (Lys(78)-Ala(440)), we have named this protein A(61). Unlike angiostatin, A(61) was produced in vitro from plasmin autodigestion in the absence of sulfhydryl donors. A(61) bound to lysine-Sepharose and also underwent a large increase in fluorescence yield upon binding of the lysine analogue, trans-4-aminomethylcyclohexanecarboxylic acid. Circular dichroism suggested that A(61) was composed of 21% beta-strand, 14% beta-turn, 18% 3(1)-helix and 8% 3(10)-helix. A(61) was an anti-angiogenic protein as indicated by the inhibition of bovine capillary endothelial cell proliferation. Plasminogen was converted to A(61) by HT1080 cells and bovine capillary endothelial cells. Furthermore, a plasminogen fragment similar to A(61) was present in the serum of humans as well as normal and tumor-bearing mice. These results establish that plasmin turnover can generate anti-angiogenic plasmin fragments in a nonpathological setting.
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PMID:Purification and characterization of A61. An angiostatin-like plasminogen fragment produced by plasmin autodigestion in the absence of sulfhydryl donors. 1111 3