Biochemical and biological activities of the venom of the Chinese pitviper Zhaoermia mangshanensis, with the complete amino acid sequence and phylogenetic analysis of a novel Arg49 phospholipase A2 myotoxin.
Zhaoermia mangshanensis (formerly Trimeresurus mangshanensis, Ermia mangshanensis) represents a monotypic genus of pitviper known only from Mt Mang in China's Hunan Province, and is among the largest and most spectacular of Asian venomous snakes. The venom of Zhaoermia exhibits high coagulant activity on bovine and human fibrinogen and human plasma, high phosphodiesterase and arginine ester hydrolytic activity, and moderate to low l-amino acid oxidase, kallikrein, caseinolytic, phospholipase A(2) (PLA(2)), haemorrhagic and myotoxic activities. The approximate i.p. LD(50) of the venom in mice was estimated to be 4 mg/kg. We purified the major toxin of Zhaoermia venom by gel-filtration, cation-exchange chromatography and HPLC. The toxin, a homodimer with an experimental monomeric mass of 13,972 Da, induced edema and myonecrosis in mice, but was devoid of detectable PLA(2) catalytic activity. Its complete amino acid sequence is composed of 121 amino acid residues cross-linked by seven disulfide bridges, and shows more than 80% identity to two Lys49-PLA(2)s from distantly related Asian pitvipers, Protobothrops mucrosquamatus and Calloselasma rhodostoma. Phylogenetic analysis of the novel toxin, zhaoermiatoxin, confirmed that it is rooted within a comprehensive sample of Lys49-PLA(2)s despite having an arginine residue in position 49, suggesting a secondary Lys49-->Arg substitution which did not alter the catalytic inactivity of the molecule.
Mebs
Dietrich
D
Zentrum der Rechtsmedizin, Klinikum der Johann Wolfgang Goethe-Universität, Kennedyallee 104, D-60596 Frankfurt am Main, Germany.
Kuch
Ulrich
U
Coronas
Fredy I V
FI
Batista
Cesar V F
CV
Gumprecht
Andreas
A
Possani
Lourival D
LD
D000595:Amino Acid Sequence; D000818:Animals; D002681:China; D003435:Crotalid Venoms / Q000201:enzymology*; D008969:Molecular Sequence Data; D010741:Phospholipases A / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D054467:Phospholipases A2; D010802:Phylogeny; D017819:Viperidae
D003435:Crotalid Venoms; D010741:Phospholipases A; D054467:Phospholipases A2