PAT-SPLITTING ENZYMES 173 



of esters both of mono-basic and of di-basic acids. They 

 proposed a provisional hypothesis, according to which the 

 hydrolysis of ethereal salts by lipase involves the direct 

 association of the enzyme with the carboxyl group. Where 

 these groups are close together hydrolysis appears to take 

 place more readily than when they are separated ; thus, ethyl 



is more readily broken up than ethyl 



CHgCOjCgHg 



, while ethyl malonate, CHOH 



CH3CO2C2H5 



occupies an intermediate position. 



They concluded that the difierence between animal and 

 vegetable hpase is one of degree, and if sufficient enzyme 

 is used almost all esters are more or less attacked. 



Kastel and Loevenhart made use of animal lipase in the 

 following way : they macerated fresh pancreas with coarse 

 sand, extracted the enzyme with water or glycerine, 1 c.c. 

 of the extract from either 10, 20 or 50 grams of tissue 

 was diluted to 100 c.c. and allowed to act for forty minutes 

 on a mixture of 4 c.c. of water, O'Ol c.c. toluene, and 0-25 c.c. 

 of ethyl but3T:ate at 40°C., the mixture being afterwards 

 titrated with ^ potash solution. They found that the 

 enzyme was destroyed at a temperature of 60° to 70° C, 

 and that most antiseptics had an injurious effect on it, 

 especially sodium fluoride and mineral acids. 



By titrating the solutions at definite intervals of time they 

 obtained results which led them to the following conclusions : — 



