LIPASE 369 



and Wartenberg,* with the result that it has been found that 

 the seeds of Euphorbiaceae, and especially castor-oil seeds, 

 whether germinating or not, contain an enzyme capable of 

 hydrolysing fats. Lipase may occur in the seed as in the 

 castor-oil, or it may develop during germination as in linseed. 

 The fact that hydrolysis is slow at first and then suddenly in- 

 creases from 5 per cent after one day to 58 per cent after two 

 days and to 95 per cent after four days led Connstein to the 

 conclusion that for rapid hydrolysis a certain minimum amount 

 of free acid must be present, and it was found that when a 

 little free acid was added from the commencement hydrolysis 

 could be completed within a few hours. Similar observations 

 regarding the curve of the hydrolysis of fats during the ger- 

 mination of Ricinus seeds have been made by Delcano.f 



According to Nicloux J fats may be attacked by other 

 ^Cleans. He used castor-oil seeds, which were ground up and 

 the cytoplasm separated from the aleurone grains and other 

 cell contents by mechanical means. 



It was found that the cytoplasm thus prepared showed a 

 marked power of hydrolysing fats, acting in the same way as 

 an enzyme and obeying the laws of enzyme action. But inas- 

 much as the active substance, which Nicloux calls lipasei'dine, 

 contained in the protoplasm is destroyed by water as soon as 

 its protective layer of fat is removed, it is not considered to be 

 an enzyme in the ordinary sense of the term. 



The most favourable conditions for the activity of lipase 

 may be summarized as follows : 



(a) The presence of free acid varying from N/6o to N/ioo 

 or less, according to the amount of material to be hydrolysed. 



(b) The presence of a certain amount of water. 



(c) The formation of a good emulsion. 



(d) The maintenance of a suitable optimum temperature, 

 varying from about 23 to 42 C. 



THE ISOLATION OF LIPASE*. 



Lipase may be separated from the seeds of Ricinus by the 

 following means : The seeds are allowed to begin germination ; 



* Connstein, Hoyer, and Wartenberg: " Ber deut. chem. Gesells.," 1902, 

 3S 3988; Hoyer: id., 1904, 37, 1441 ; " Zeit. Physiol. Chem.," 1907, 50, 414. 

 fDelcano : "Centrlbl. Bakt.," 1909, 24, 130. 

 Nicloux : " Proc. Roy. Soc., Lond.," B., 1906, 77, 454. 



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