Diversity of human plasma protein C inhibitor.
Protein C inhibitor was purified from human plasma by use of a dermatan sulfate or heparin column, followed by hydroxyapatite, gel filtration and ion exchange columns. A dimer of protein C inhibitor was detected by SDS-PAGE under reducing conditions, in addition to two forms of monomer species. One of the monomers, 52-kDa PCI, formed a stable complex with activated protein C, urokinase, plasma and tissue kallikrein, but the dimer species and 48-kDa PCI were inactive. When the monomer and dimer forms of protein C inhibitor were applied to 2D-PAGE, more than 20 spots were observed by Western blot analysis and were confirmed to be protein C inhibitor by MALDI-TOF mass spectrometry. The heterogeneity of the protein C inhibitor species was not due to glycosylation or phosphorylation.
Department of Biochemistry, Faculty of Medicine, Kinki University, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511, Japan. asaito@med.kindai.ac.jp
Akio
A
Saito
D000595:Amino Acid Sequence; D003871:Dermatan Sulfate / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008969:Molecular Sequence Data; D020842:Plasma Kallikrein / Q000378:metabolism; D011486:Protein C / Q000037:antagonists & inhibitors / Q000378:metabolism; D018046:Protein C Inhibitor / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D055503:Protein Multimerization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D020840:Tissue Kallikreins / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
D011486:Protein C; D018046:Protein C Inhibitor; D003871:Dermatan Sulfate; D020842:Plasma Kallikrein; D020840:Tissue Kallikreins; D014568:Urokinase-Type Plasminogen Activator