Regulation mechanism of the serine protease activity of plasma hyaluronan binding protein.
The inhibitor for the serine protease activity of plasma hyaluronan binding protein (PHBP) was purified from human plasma by polyethylene glycol (PEG) fractionation, diethylaminoethyl (DEAE)-Sephacel ion-exchange chromatography, Phenyl Toyopearl 650M hydrophobic chromatography, Bio Gel A-0.5 m gel-filtration and hydroxyapatite chromatography. The serine protease activity of PHBP was measured with Boc-Phe-Ser-Arg-methylcoumarine amide (MCA) as the synthetic substrate of PHBP. The results of the amino acid sequence analyses of the purified PHBP inhibitor indicated that it was C1 inhibitor of the serpin family. C1 inhibitor formed a complex with PHBP, suggesting that it is the actual inhibitor of PHBP in human plasma. On the other hand, dextran sulfate and phosphatidylethanolamine enhanced the auto-fragmentation and the serine protease activity of pro-PHBP, but kaolin did not. These results suggested that the serine protease activity of PHBP was regulated in a similar manner to that of factor XII of the coagulation system.
Department of Physiological Chemistry, School ol Pharmaceutical Sciences, Showa University, Tokyo, Japan. nammiura@pharm.showa-u.ac.jp
N H
NH
Choi-Miura
K
K
Saito
K
K
Takahashi
M
M
Yoda
M
M
Tomita
D000596:Amino Acids / Q000032:analysis; D015153:Blotting, Western; D002848:Chromatography, DEAE-Cellulose; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D005174:Factor XII / Q000737:chemistry; D006801:Humans; D018960:Hyaluronan Receptors / Q000302:isolation & purification* / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000097:blood* / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology*
D000596:Amino Acids; D018960:Hyaluronan Receptors; D015842:Serine Proteinase Inhibitors; D005174:Factor XII; D012697:Serine Endopeptidases