Comparative proteomics and subtyping of venom phospholipases A2 and disintegrins of Protobothrops pit vipers

To explore the venom diversity and systematics of pit vipers under the genus Protobothrops, the venom phospholipases A(2) (PLA(2)s) Of P. mangshanensis, P. elegans and P. tokarensis were purified and characterized for the first time. The results were compared with the corresponding venom data of other co-generic species including P. mucrosquamatus, P. flavoviridis and P. jerdonii. Based on sequence features at the N-terminal regions, we identified five PLA(2) subtypes, i.e., the Asp49-PLA(2)s with N6, E6 or R6 substitution and the Lys49PLA(2). However, not all subtypes were expressed in each of the species. Venom N6-PLA(2)s from P. mangshanensis and P tokarensis venom were weakly neurotoxic toward chick biventer cervicis tissue preparations. The venoms of P tokarensis and P flavoviridis contained identical PLA(2) isoforms. In most Protobothrop disintegrins, sequences flanking the RGD-motif are conserved. Phylogenetic analyses based on amino acid sequences of both families of the acidic PLA(2)s and the disintegrins clarify that these species could belong to a monophyletic group. (C) 2004 Elsevier B.V. All rights reserved.