Molecular characterization of a weak fibrinogen-clotting enzyme from Trimeresurus jerdonii venom.
A fibrinogen-clotting enzyme designed as jerdonobin-II was isolated from the venom of Trimeresurus jerdonii. It differed in molecular weight and N-terminal sequence with the previously isolated jerdonobin, a thrombin-like enzyme from the same venom. The enzyme consists of a single polypeptide chain with molecular weights of 30,000 and 32,000 under non-reducing and reducing conditions, respectively. Jerdonobin-II showed weak fibrinogen clotting activity and its activity unit on fibrinogen was calculated to be less than one unit using human thrombin as standard. The precursor protein sequence of jerodonobin-II was deduced from cloned cDNA sequence. The sequence shows high similarity (identity=89%) to TSV-PA, a specific plasminogen activator from venom of T. stejnegeri. Despite of the sequence similarity, jerdonobin-II was found devoid of plasminogen activating effect. Sequence alignment analysis suggested that the replacement of Lys239 in TSV-PA to Gln239 in jerdonobin-II might play an important role on their plasminogen activating activity difference.
Jin
Yang
Y
Department of Animal Toxinology, Kunming Institute of Zoology, the Chinese Academy of Sciences, East Jiao-Chang Road, Kunming 650223, Yunnan, People's Republic of China.
Lu
Qiu-Min
QM
Chen
Run-Qiang
RQ
Wu
Jian-Bo
JB
Xiong
Yu-Liang
YL
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001777:Blood Coagulation / Q000187:drug effects*; D003435:Crotalid Venoms / Q000201:enzymology*; D005340:Fibrinogen / Q000737:chemistry*; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity; D017841:Trimeresurus
D003435:Crotalid Venoms; D005340:Fibrinogen; D012697:Serine Endopeptidases