NON-OXIDATIVE ENZYMES OF SPORE EXTRACTS 139 



Table III 

 The effect of heat shook prior to disruption upon enzymatic activity 



System 



* Minutes of Heat Shock at 65°C. 

 t Activity in presence of AMP 



occur naturally in germination without heat shock and also may explain why 

 heat shock appears to be stimulatory to germination. It is possible that the 

 intact resting spore consists of a self-regulating system which may be com- 

 posed of components inhibitory to germination, thus maintaining a resting 

 state. Heat shock may remove such inhibition normally destroyed by some 

 such proteolytic mechanisms suggested by Dr. Levinson. Recent work by 

 Swartz et al (1956) on enzymes of Proteus vulgaris which were found in 

 extracts after boiling for 2 minutes and which retained 50% activity after 15 

 minutes boiling was explained by the discovery of an inhibitor, apparently a 

 protein, destroyed by heat. Of interest, in view of Dr. Levinson's suggestions, 

 is the fact that one of the heat-activated enzymes was a pyrophosphatase. 



TTie results of the heat shock experiments might also furnish a means of 

 determining whether an enzyme is involved in germination or sporulation. 

 Heat-lability in the intact spore could indicate a relationship to sporulation 

 rather than germination, while heat-stability could indicate either a specific 

 role in germination or a general role in all the cell processes. A differential 

 activation would certainly indicate an important function in germination. 



Fig. 1 represents some possible functions of these enzyme? in the synthesis 

 of a spore peptide recently studied and characterized by Strange and Powell 

 (1954) and Strange and Dark (1956). The peptide is found in the spores 

 of B. cereus and two other species and is extruded during germination. It 

 is associated with the spore coat, and its components are glutamic acid, 

 alanine, acetyl glucosamine, alpha-epsilon diaminopimelic acid, and an un- 

 identified hexosamine. Powell and Strange have suggested that the enzymatic 

 depolymeryzation or detachment of this peptide from the spore coat may be 

 one of the first stages of germination. 



It should be emphasized that the role of these enzymes in the synthesis and 

 hydrolysis of the spore peptide is at present only speculative. Nevertheless, it 

 is ^attractive in that the suggested functions relate the enzymes both to sporu- 

 lation and germination. 



In respect to peptide svnthesis, the synthetase (GS) and glutamotransferase 

 (GTF) offers a means of synthesis of a possible peptide component as well as 



