Characterization of venom (Duvernoy's secretion) from twelve species of colubrid snakes and partial sequence of four venom proteins

R.E. Hill and S.P. Mackessy. Characterization of venom (Duvernoy's secretio n) From twelve species of colubrid snakes and partial sequence of four Veno m proteins. Toxicon XX, xx-yy, 2000. - Venomous colubrids, which include mo re than 700 snake species worldwide, represent a vast potential source of n ovel biological compounds. The present study characterized venom (Duvernoy' s gland secretion) collected from twelve species of opisthoglyphous (rear-f anged) colubrid snakes, an extremely diverse assemblage of nonvenomous to h ighly venomous snakes. Most venoms displayed proteolytic activity (casein), though activity levels varied considerably. Low phosphodiesterase activity was detected in several venoms (Amphiesma stolata, Diadophis punctatus, He terodon nasicus kennerlyi, H. n. nasicus and Thamnophis elegans vagrans), a nd acetylcholinesterase was found in Boiga irregularis saliva and venom, bu t no venoms displayed hyaluronidase, thrombin-like or kallikrein-like activ ities. High phospholipase A(2) (PLA(2)) activity was found in Trimorphodon biscutatus lambda venom, and moderate levels were detected in Boiga dendrop hila and D. p, regalis venoms as well as B. dendrophila and H. n. nasicus s alivas. Non-reducing SDS-PAGE revealed 7-20 protein bands (3.5 to over 200 kD, depending on species) for all venoms analyzed, and electrophoretic prof iles of venoms were typically quite distinct from saliva profiles. Componen ts from A. stolata, Hydrodynastes gigas, Tantilla nigriceps and T. e. vagra ns venoms showed protease activity when run on gelatin zymogram gels. N-ter minal protein sequences for three 26 kD venom components of three species ( H. gigas, N torquata, T. biscutatus) and one 3.5 kD component (T. nigriceps ) were also obtained, and the 3.5 kD peptide showed apparent sequence homol ogy with human vascular endothelial growth factor. these data represent the first sequences of colubrid venom components. Protease. phosphodiesterase and PLA(2) activities are also common to elapid and viperid snake venoms, b ut it is apparent that numerous other (ns yet undescribed) components make up the majority of colubrid venom proteins. Thr: complex nature of venoms p roduced by most species surveyed, and the high levels of protease or phosph olipase Az activity of some venoms, suggest that many colubrids could becom e an important source of human health concern as encounters with these snak es increase. (C) 2000 Elsevier Science Ltd. All rights reserved.