476 ENZYMES 



destroyed. The rapidity of the disappearance of the blasto- 

 Hpase depends on the hydrogen ion concentration ; at P^ 47 

 the decHne is faster than at P^ 7. 



In support of their conclusion that the blastoHpase arises 

 from the proteolysis of the original enzyme complex, Willstatter 

 and Waldschmidt-Leitz found that the treatment of spermato- 

 lipase with pepsin yielded a product having the same properties 

 as blastolipase. 



THE PREPARATION OF LIPASE. 



Ricinus lipase has certain peculiar properties which make 

 it extremely difficult to obtain an active preparation in a state 

 of relative purity. It is, for example, insoluble in water, and 

 its separation from fat renders it inactive; further, it is sensi- 

 tive to such organic substances as alcohol, glycerol, etc. Will- 

 statter and Waldschmidt-Leitz have elaborated a method of 

 preparation which involves dialysis, centrifuging, adsorption 

 on kaolin and drying, for the details of which the original paper 

 must be consulted. 



For commercial purposes the enzyme is prepared as fol- 

 lows : * Castor-oil seeds are ground up with water and then 

 centrifuged ; the resulting emulsion, which contains castor 

 oil, proteins, and the enzyme, is then allowed to ferment at a 

 temperature of 24°, whereby a scum containing the ferment 

 rises to the surface and can be separated from the aqueous 

 layer. This scum is then allowed to act upon the molten fat 

 in the presence of water and a little manganese sulphate as a 

 catalytic agent. 



PROPERTIES. 



Ricinus lipase, comprising both spermato- and blastoHpase, 

 is insoluble in water, and if it be rendered free from fat, its 

 activity is lost ; according to Willstatter and Waldschmidt- 

 Leitz this is due to an alteration in the colloid state of aggre- 

 gation both of the enzyme and its carrier, since this loss of 

 activity can be considerably reduced by using finely divided 

 carriers, such as kieselguhr, as diluents in the process of fat 

 extraction. 



* Cf. Hoyer : " Die Seifenfabrikant, " 1905, 25, 649. 



