FERMENTS IN SNAKE VENOM 211 



we still have a long way to travel through the most complex and misleading 

 paths of study. I propose, therefore, to record only the facts already obtained 

 by various investigators up to the present moment. 



PROTEOLYTIC ACTION OF SNAKE VENOM. 



Flexner and Noguchi, with a view to finding a suitable explanation of the 

 softening effect of venom upon muscle, described so fully and graphically by 

 Mitchell and Reichert, carried out a series of experiments for determining 

 whether or not venom contains a proteolytic ferment. As the softening of 

 muscle takes place quickly, within 30 minutes to a few hours, the operation 

 of bacteria can be excluded. Several proteid substances were exposed to 

 venom in sterile saline solutions, prepared by passing the dissolved venom 

 through the Chamberland filter. In some experiments the solution was kept 

 under a layer of toluol. Gelatin in 10 per cent solution was mixed with 

 crotalus and cobra venom in solutions containing 10 mg. of dried venom. 

 Cobra venom brought about complete liquefaction in two days, crotalus in 

 16 hours. Fibrin heated to coagulation (60 to 62 C.) is not attacked by 

 venom; coagulated egg-albumin is also unaffected. On the other hand, raw 

 fibrin obtained from dog, rabbit, and guinea-pig is easily and more rapidly 

 fragmented by venom than in the control tubes. Venoms heated to 75 C. 

 for 30 minutes lose their liquefying property. The addition of Calmette 

 antivenin does not influence the result. 



Muscle in thin slices was taken from the pigeon and guinea-pig; 2 per cent 

 solution of venom (cobra, crotalus, water-moccasin) was filtered through the 

 Chamberland bougie. To one set of tubes the muscle was added; to another 

 set, muscle plus the sterile serum of the animal; while in a third the muscle 

 minus venom was placed. The control tubes showed no change to the naked 

 eye after 6 hours' contact. The temperature was 36 C. In the other tubes 

 changes were noticed in 2 hours. At this period the muscle was opaque, 

 swollen, and of a grayish color, and the fibers were separated. In 3 hours the 

 swelling and separation of the fibers had increased, and by shaking the tubes 

 the slices of muscle could be easily broken up. In 6 hours disintegration was 

 complete. 



Crotalus serum is without liquefying action upon gelatin. 



Flexner and Noguchi concluded, therefore, that venom contains a body 

 capable of modifying protein, and upon this the softening effect of muscle 

 tissue in corpore doubtless depends. 



Delezenne l has established the existence in venoms of a kinase analogous 

 to the kinase of leucocytic origin and to enterokinase. The venom alone 

 does not attack the heat-coagulated egg-albumin, but it confers upon the 

 inactive pancreatic juice an intense digestive power. The venom of Lachesis 

 is shown to be the richest in kinase. It digests gelatin completely and after 

 the latter is subjected to the action of this venom it becomes incapable of 

 solidification. 



1 Delezenne. Sur 1'action kinatique des venins. C. R. Ac. des Sc., 1902, CXXXV, 339. 



