PRIMING REACTIONS 



211 



In the presence of the same enzyme, methylglycine or sarcosine is 

 degraded as follows : 



CH3NHCH2COOH + iO, -^ CH3NH2 + CHO— COOH 



methylamine glyoxylic acid 



Another specific enzyme of oxidative deamination is glutamic acid 

 dehydrogenase. This is an anaerobic dehydrogenase: 



L-glutamic acid 



Imino acid of 

 glutamic acid 



DPN 



TPN 



DPNH2 

 TPNH 



L-glutamic acid 

 dehydrogenase 



2H- 



respiratory chain 



a — ^ketoglutaric acid 



spontaneous reaction 

 ^NHa 



FAD can utilize molecular oxygen as an electron acceptor and hydrogen 

 peroxide is formed. The oxidative deamination of an amino acid in the 

 presence of an amino acid oxidase containing FAD can be written as 

 follows: 



R R 



NH2— CH— COOH + F AD->N H=C-COOH + F ADH^ 



R R 



NH=C— COOH + H20-*0=C— COOH + NH, 



FADHo+02-^FAD+H,02 



catalase 



H2O 



2^^2 



->HoO+— O2 

 2 



R 



R 



NH2-CH-COOH4- — 02-^0=C-COOH+NH3 



2 



