MUCOLYTIC ENZYMES 



Wollmann and Wollmann (42) found, however, that an enzyme 

 obtained from staphylococci which had been lysed by phage lysed 

 sarcinae, organisms sensitive to lysozyme. Pirie (35) found that 

 lysozyme from egg white released a specific phage from its union with 

 heat-killed cultures of B. megatherium, a release which occurred during 

 the same interval of time as hydrolysis of the bacterial polysaccharide 

 by the lysozyme. Heat-killed bacilli incubated with lysozyme could 

 no longer absorb phage. 



Anderson, in a recent paper (4), reported the separation of a 

 lytic principle derived by ultraviolet irradiation from a phage of 

 Escherichia coli. The phage was purified by low- and high-speed 

 centrifugation. After irradiation with ultraviolet light, the appar- 

 ently homogeneous and pure phage was split into two components, 

 one of which was a low molecular weight protein found in the super- 

 natant fluid after ultracentrifugation. This protein of low molecular 

 weight caused the lysis of E. coli cells killed by ultraviolet irradiation. 

 The killed coli cells also could be lysed by crystalline lysozyme from 

 egg white. The lytic agent obtained from phage, however, could not 

 replace lysozyme in the lysis of M. lysodeikticus . 



Northrop (34) found that suspensions of a highly purified phage 

 specific for iS". muscae caused the immediate lysis of suspensions of resting 

 living staphylococci but not of killed organisms. This organism is 

 killed (and lysed after alkalinization) by egg-white lysozyme (40). 

 From this staphylococcus, killed by acetone, a fraction was obtained 

 which not only lysed suspensions of the same species, but also a strain of 

 Sarcina lutea. 



An explanation of these and other experiments may be at- 

 tempted along the following lines. Phage virus according to this 

 hypothesis has two components, one a highly specific substance of very 

 high molecular weight, the other a less specific component of lysozyme- 

 like nature which causes the actual lysis of the infected bacterial cells. 

 The lytic agent may be a normal component of the bacterial cell. 



What are the functions of lysozyme in the microbial and animal 

 organism? From a teleological standpoint, lysozyme seems to act in 

 the animal organism as a protective enzyme against bacterial invasion. 

 But the most susceptible organisms are harmless saprophytes; patho- 

 genic organisms show little, if any, susceptibility, although some have 

 been reported to be susceptible to egg-white lysozyme. 



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