Characterization of venom (Duvernoy's secretion) from twelve species of colubrid snakes and partial sequence of four venom proteins Robert E. Hill, Stephen P. Mackessy* Department of Biological Sciences, 501 20th St., University of Northern Colorado, Greeley, CO 80639- 0017, USA Received 25 June 1999; accepted 22 December 1999 Abstract R.E. Hill and S.P. Mackessy. Characterization of venom (Duvernoy's secretion) from twelve species of colubrid snakes and partial sequence of four venom proteins. Toxicon XX, xx±yy, 2000. Ð Venomous colubrids, which include more than 700 snake species worldwide, represent a vast potential source of novel biological compounds. The present study characterized venom (Duvernoy's gland secretion) collected from twelve species of opisthoglyphous (rear-fanged) colubrid snakes, an extremely diverse assemblage of non- venomous to highly 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, Heterodon nasicus kennerlyi, H. n. nasicus and Thamnophis elegans vagrans ), and acetylcholinesterase was found in Boiga irregularis saliva and venom, but no venoms displayed hyaluronidase, thrombin-like or kallikrein-like activities. High phospholipase A 2 (PLA 2 ) activity was found in Trimorphodon biscutatus lambda venom, and moderate levels were detected in Boiga dendrophila and D. p. regalis venoms as well as B. dendrophila and H. n. nasicus salivas. Non-reducing SDS± PAGE revealed 7±20 protein bands (3.5 to over 200 kD, depending on species) for all venoms analyzed, and electrophoretic pro®les of venoms were typically quite distinct from saliva pro®les. Components from A. stolata, Hydrodynastes gigas, Tantilla nigriceps and T. e. vagrans venoms showed protease activity when run on gelatin zymogram gels. N-terminal 0041-0101/00/$ - see front matter 7 2000 Elsevier Science Ltd. All rights reserved. PII: S0041-0101(00)00091-X Toxicon 38 (2000) 1663±1687 www.elsevier.com/locate/toxicon * Corresponding author. Tel.: +1-970-351-2429; fax: +1-970-351-2335. E-mail address: spmacke@bentley.unco.edu (S.P. Mackessy).