Human Neutrophil Elastase Alters Human a-Thrombin Function: Limited Proteolysis Near the ‘y-Cleavage Site Results in Decreased Fibrinogen
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چکیده
During blood coagulation. polymorphonuclear leukocytes release elastase in amounts that can exceed 100 nmol/L. We therefore studied the interaction between human leukocyte elastase and human a-thrombin. Elastase cleaved the thrombin B chain (Ala 1 50-Asn 1 51 ) near the “y-cleavage site, resulting in two fragments held together by noncovalent interactions. The NH2-terminal fragment (Fl). mol wt -18,000. was disulfide-linked to the thrombin A chain. The COOH-terminal fragment (FlI). mol wt 1 3.000. contained the active-site serine and formed a covalent bond with antithrombin Ill. Heparin accelerated proteolysis of a-thrombin by elastase. Proteolyzed a-
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تاریخ انتشار 2005