310 IMMUNO-CATALYSIS 



the observation of Delezenne and Ledebt tbat the action of snake 

 venom first progresses to the hemolytic peak and then declines. It is 

 interesting to note that both of these enzymes w^ere neutralized by 

 antivenom serum as demonstrated by the findings of Delezenne and 

 Ledebt. 



In a subsequent study Delezenne and Fourneau (1914) undertook 

 a systematic investigation regarding the nature of the hemolytic leci- 

 thin derivative. They found that fresh sterile cobra venom acting on 

 vitellin from egg yolk at 50°C. transforms lecithin completely into a 

 white substance having a high degree of hemolytic activity. One mg. 

 of snake venom was found capable of transforming 200 g. of lecithin. 

 The amount of lecithinase contained in 1 g. of crude snake venom was 

 capable of catalyzing 200,000 g. of lecithin, which naturally excludes 

 any possibility of a chemical reaction between venom and lecithin in 

 a stoichiometrical sense. Furthermore the venom after its action on 

 lecithin could be recovered and used again. They isolated from the 

 reaction mixture the hemolytic substance in the form of rectangular 

 rod-like crystals, and identified it as anhydrous monopalmitic lecithin 

 (monopalmitophosphoglyceric ester of choline) which is now known 

 as lysolecithin or lysocithin. 



Levene, Rolf and Simms (1924) found, on the other hand, that the 

 action of cobra venom on egg yolk yields a mixture of lysolecithin and 

 lysocephalin. Twenty yolks were diluted with 600 ml. of M/15 

 phosphate solution of pH 7.0 (venom lecithinase is active at pH 6.5 

 to 7.5; it is entirely inactivated at pH 8). The phosphate suspension of 

 egg yolk was digested with 0.1 g. of cobra venom for 14 hours at 40°C. 

 A concentrate of the alcoholic extract was treated with a concentrated 

 solution of cadmium chloride to precipitate lysolecithin and lyso- 

 cephalin. Lysocephalin is the more insoluble in organic solvents and 

 was purified by crystallization from a solution in chloroform. It crystal- 

 lizes as transparent needles which soften at 140°C. and melt at 198°C. 

 with decomposition. On hydrolysis of lysocephalin only one acid, 

 namely stearic acid, could be isolated. Lysolecithin is very much more 

 soluble than lysocephalin; it may be crystallized from chloroform, 

 pyridine, and methyl and ethyl alcohols in aggregates of needles. It 

 softens at 100°C. and decomposes at 263°C. (On hydrolysis lysoleci- 

 thin yielded palmitic and stearic acids.) 



Experiments carried out by Noguchi showed that both lysolecithin 



