363 



Studies on Enzyme Action. XVII. — Enzymes of the\' Emulsin 

 Type. (II) The Distribution of fi-Enzymes in Plants. 

 By H. E. Armstrong, F.R.S., E. F. Armstrong, and E. Horton. 

 (Received April 3 —Read May 16, 1912.) 



In extending our search for enzymes of the emulsin type, during the past 

 two years, we have examined a large number of species of plants, using for 

 the purpose the following method briefly referred to in the previous paper, as 

 in most cases we found that active extracts could not be obtained directly 

 from the leaf material. 



Usually, as soon as possible after it has been collected, we have placed the 

 plant in a bottle with toluene, both in order to prevent the development 

 of moulds and to give full opportunity to the enzymes within the cells 

 to resolve the various hydrolytes with which they are associated. Such 

 material can be dealt with at leisure. It is first cut up in a mincing mill 

 and then dried — either directly or after it has been thoroughly washed to 

 deprive it of soluble matter — best by exposure in a vacuum desiccator at 

 air temperatures ; the washed material has the advantage that little or no 

 correction has to be applied subsequently, in the course of the analytical 

 process, on account of soluble matter, such as reducing sugars and tannins, 

 which disturb the result, if present. But in most eases washing diminishes 

 the activity of the material. In determining the original activity of the 

 plant material, it is, of course, necessary to dry it without washing. The 

 dried material is finally prepared for use by grinding it to a fine powder in a 

 coffee mill. Such powder apparently may retain its activity over long periods. 



We have used hitherto as hydrolytes the four glucosides : linamarin, 

 amygdalin, prunasin and salicin, our primary object being to determine the 

 distribution of the four enzymes : linase, amygdalase, prunase and salicase. 



The method adopted has been to add the dried powder, prepared in the 

 manner described, to a solution containing one-fifth of a molecular 

 proportion of the glucoside per 1000 c.c, using solution and powder in 

 the proportion of 100 c.c. to 1 grm. After digesting the mixture at 37° 

 vol. lxxxv. — b. 2 c 



[International Catalogue of Scientific Literature. 

 Author's title slip : — D. M. 

 Subject slips : — 



Distribution of /3-enzymes in plants. 



D 8014 Enzymes of the emulsin type. 



D 6525 Detection and distribution of /3-enzymes in plants.] 



