NON-OXIDATIVE ENZYMES OF SPORE EXTRACTS 1 11 



crassa by Leloir and Cardini (1953). TFie presence of the synthetase and 

 kinase systems in spores suggests that tlie amination of hexose by glutaniine 

 and its subsequent acetylation should be demonstrable and such studies are 

 now in progress. 



While the above mentioned enzymes can be related to spore peptide sn n- 

 thesis, the unidentified transferase has properties which suggest that it could 

 function in peptide hydrohsis. The stimulation by adenosine particularh 

 suggests a function in germination. The identification of the substrate for 

 XTF activity with the spore peptide, while entirely speculative, has many 

 features which indicate a plausible relationship: ( T) the peptide is non- 

 dialyzable as is the substrate of XTF; (2) the peptide is made up of compo- 

 nents with which a transferase- hydroxylamine system could react; (3) the 

 peptide is absent from vegetative cells as is XTF activity; (4( the range of 

 liberation extends from alkaline to acid pH as does the range of XHA forma- 

 tion; and (5) the liberation or depolymerization of the peptide is probably 

 enzymatic. 



Further significance of the relationship of the peptide to XTF activity can 

 be found in recent work of Meister et al { 1955 t . These workers have demon- 

 strated that enzymes catalyzing transferase reactions with hydroxylamine also 

 catalyze the hydrolysis of these substrates. The authors suggested that the 

 transfer, hydrolysis and synthesis reactions are catalyzed by the same enzyme. 

 This idea, together with the demonstrated activity of XTF as a transferase and 

 its probable relationship to germination, suggests that XTF may be the 

 enzyme responsible for the spore peptide depolymerization. This concept 

 should be susceptible to direct experimental test. If it proves incorrect, 

 two important problems still remain: (1) what is the substrate in the XTF 

 system, and (2) what enzyme is responsible for peptide depolymerization? 



References 



Fry, B. A. 1954. Glutamine synthesis by Micrococcus pyogenes var. aureus. 



Biochem. J. 59: 579-589. 

 Grossowicz, N. E. Wainfan, E. Borek, and H. Waelsch. 1950. The enzymatic 



formation of hydroxamic acids from glutamine and asparagine. J. Biol. 



Chem. 187: 111-125. 

 Jones, M. E. and F. Lipmann. 1955. Aceto-CoA-kinase. Methods of Enzy- 



mology 1: 585-591. Academic Press, Inc., New York. 

 Krask, B. J. 1953. Methionine sulfoxide and specific inhibition of sporula- 



tion in Bacillus suhtilis. J. Bact. 66: 374. 

 Leloir, L. F. and C. E. Cardini. 1953. The biosynthesis of glucosamine. 



Biochem. and Biophys. Acta 12: 15-22. 

 Meister. A., L. Levintow. R. Greenfield, and P. Abendschein. 1955. Hy- 

 drolysis and transfer reactions catalyzed by omega-amidase preparations. 



J. Biol. Chem. 215: 441-460. 



