KARL MEYER 



mucopolysaccharide of high molecular weight, forming extremely 

 viscous aqueous solutions. It precipitates rabbit antisera against 

 M. lysodeikticus in a dilution of 1 : 1,000,000. Crystalline lysozyme in a 

 concentration of 1 to 5 mg. immediately precipitates 10 mg. of the 

 polysaccharide, as does protamine. In a concentration of a few 

 gamma, lysozyme abolishes within a few minutes the viscosity of 

 aqueous solutions of the polysaccharide. On incubation for two hours, 

 the hydrolysis of glucosidic linkages is almost complete. In the 

 presence of 1 mg. of the polysaccharide, the lytic action of lysozyme 

 on living M. lysodeikticus is decreased approximately 100-fold, indicating 

 a competition for the enzyme between the added substrate and the 

 substrate contained in the microorganism. 



The action of lysozyme on this carbohydrate from M. lysodeik- 

 ticus is highly specific. Organ extracts and enzyme preparations which 

 contain no lysozyme have no depolymerizing effect on the carbo- 

 hydrate, while lysozyme from sources other than egg white depoly- 

 merizes the carbohydrate. From organisms pretreated with lysozyme, 

 no mucopolysaccharide fraction was obtained which Ulcerated re- 

 ducing groups when brought into contact with lysozyme. 



The mucopolysaccharide appears to be firmly bound to the 

 bacterial membrane. The primary mechanism of lysozyme action 

 apparently consists of a depolymerization of this mucopolysaccharide, 

 leading to water imbibition by the organism and to disorganization of 

 the microbial cell. The breakdown of protein and of organic phos- 

 phates are effects due to autolytic enzymes, which are apparently re- 

 sponsible for some part of the visible clearing of the bacterial suspen- 

 sions. 



It early became obvious to Fleming and his co-workers that 

 lysozyme was not identical with bacteriophage. But it appears from 

 available data that lysozyme or lysozyme-like enzymes are associated 

 with phage activity. As the result of the work of several investi- 

 gators—Gratia and Rhodes (14), Twort (41), WoUmann and Woll- 

 mann (42) — it seems established that, in some cases, as a result of phage 

 action, a lytic enzyme is released which is capable of dissolving" 

 heat-killed and phage-resistant living organisms of the same species 

 as the lysed strain. The.se lytic agents apparently originate in the 

 bacterial cells and in most instances can be expected to ha\'e speci- 

 ficities other than that of lysozyme. 



280 



