title: Characterization of three fibrinogenolytic enzymes from Chinese green tree viper (Trimeresurus stejnegeri) venom.
abstract: From the venom of Chinese green tree viper (Trimeresurus stejnegeri), three distinct fibrinogenolytic enzymes: stejnefibrase-1, stejnefibrase-2 and stejnefibrase-3, were purified by gel filtration, ion-exchange chromatography and reverse-phase high-performance chromatography (HPLC). SDS-PAGE analysis of those three enzymes showed that they consisted of a single polypeptide chain with mol. wt of 50000, 31000 and 32000, respectively. Like TSV-PA (a specific plasminogen activator) and stejnobin (a fibrinogen-clotting enzyme) purified from the same venom, stejnefibrase-1, -2 and -3 were able to hydrolyze several chromogenic substrate. On the other hand, different from TSV-PA and stejnobin, stejnefibrase-1, -2 and -3 did not activate plasminogen and did not possess fibrinogen-clotting activity. The three purified enzymes directly degraded fibrinogen to small fragments and rendered it unclottable by thrombin. Stejnefibrase-2 degraded preferentially Bbeta-chain while stejnefibrase-1 and -3 cleaved concomitantly Aalpha and Bbeta-chains of fibrinogen. None of these proteases degraded the gamma-chain of fibrinogen. When correlated with the loss of clottability of fibrinogen, the most active enzyme was stejnefibrase-1. The activities of the three enzymes were inhibited by phenylmethylsulfonyl fluoride (PMSF) and p-nitrophenyl-p-guanidinobenzoate (NPGB), indicating that like TSV-PA and stejnobin, they are venom serine proteases.
authors.affiliation: Department of Animal Toxinology, Kunming Institute of Zoology, Chinese Academy of Sciences, Yunnan.
authors.forename: R
authors.initials: R
authors.lastname: Gao
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: Q X
authors.initials: QX
authors.lastname: Meng
authors.forename: W H
authors.initials: WH
authors.lastname: Lee
authors.forename: D S
authors.initials: DS
authors.lastname: Li
authors.forename: Y L
authors.initials: YL
authors.lastname: Xiong
authors.forename: W Y
authors.initials: WY
authors.lastname: Wang
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects; D002681:China; D002863:Chromogenic Compounds / Q000737:chemistry; D003435:Crotalid Venoms / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D005340:Fibrinogen / Q000378:metabolism*; D008970:Molecular Weight; D011480:Protease Inhibitors / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D013379:Substrate Specificity; D017841:Trimeresurus / Q000378:metabolism*
chemical_list: D002863:Chromogenic Compounds; D003435:Crotalid Venoms; D011480:Protease Inhibitors; D005340:Fibrinogen; D012697:Serine Endopeptidases; C114079:stejnefibrase 1; C114080:stejnefibrase 2; C114081:stejnefibrase 3