CHARACTERIZATION OF A MYOTOXIN FROM THE DUVERNOYS GLAND SECRETION OF THE XENODONTINE COLUBRID PHILODRYAS-OLFERSII (GREEN SNAKE) - EFFECTS ON STRIATED-MUSCLE AND THE NEUROMUSCULAR-JUNCTION

A myotoxin has been isolated from the Duvernoy's gland (DG) secretion of the xenodontine colubrid Philodryas olfersii (green snake) by gel f iltration on Sephadex G-100 SF. Under non-reducing and reducing condit ions in SDS-PAGE, the myotoxin migrates as a single band with a mel. w t, of 20 000, The toxin has 182 amino acid residues (approximately 20% acidic), a pi of 4.8 and a blocked N-terminal, In the chick biventer cervicis preparation, P, olfersii myotoxin partially blocks potassium- evoked contractures without affecting either the twitch-tension result ing from indirect stimulation or the contractures evoked by acetylchol ine, Both the DG secretion and the myotoxin increase the serum creatin e kinase (CK) levels of mice and stimulate the release of CK from the biventer cervicis preparation in a dose- and time-dependent manner. Th e varying degrees of muscle cell lysis and extensive widening of the i ntercellular spaces caused by the DG secretion are reproduced by the m yotoxin, with the exception that in the latter the partial or total lo ss of transverse muscle striations is restricted to the muscle periphe ry. This myotoxin is the first such protein to be characterized from a DG secretion. (C) 1998 Elsevier Science Ltd. All rights reserved.