title: Protein C inhibitor: purification and proteinase reactivity.
abstract: Protein C inhibitor was purified from human plasma by a modification of a published procedure (Suzuki, K., Nishioka, J., and Hashimoto, S. J. Biol. Chem. 258, 163-168, 1983). Approximately 1 mg of pure protein was obtained from 1 L plasma, a yield of about 17%. The protein C inhibitor preparation did not lose activity over 4 weeks at 4 degrees C. Second order rate constants were measured for the inhibition of activated protein C, thrombin, and urokinase, and bimolecular complexes of protein C inhibitor with activated protein C and thrombin were visualized by denaturing polyacrylamide gel electrophoresis. Heparin accelerated the inhibition of the three proteinases in a manner consistent with a template mechanism. Plasma or pure protein C inhibitor (at the same concentration) showed the same effect of heparin on activated protein C inhibition, indicating that protein C inhibitor accounts for all the heparin-dependent inhibition of activated protein C in vivo.
authors.affiliation: Department of Medicine, University of North Carolina School of Medicine, Chapel Hill 27599.
authors.forename: C W
authors.initials: CW
authors.lastname: Pratt
authors.forename: B G
authors.initials: BG
authors.lastname: Macik
authors.forename: F C
authors.initials: FC
authors.lastname: Church
mesh_terms: D001798:Blood Proteins / Q000302:isolation & purification* / Q000502:physiology; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D011480:Protease Inhibitors / Q000302:isolation & purification*; D011486:Protein C / Q000037:antagonists & inhibitors*; D018046:Protein C Inhibitor
chemical_list: D001798:Blood Proteins; D011480:Protease Inhibitors; D011486:Protein C; D018046:Protein C Inhibitor; D006493:Heparin