374 IMMUNO-CATALYSIS 



kidney and heart. It requires cozymase I for oxidative deamination, and 

 dihydro-cozymase, or a hydrogen-donating system producing dihydro- 

 cozymase, for reductive amination of a-ketoglutaric acid. Methylene 

 blue, pyocyanine, flavin-phosphate, flavoprotein (yeast), and cyto- 

 chrome a and h preparations are found to function as carriers to vary- 

 ing degrees. According to Euler, et at. (1938) glutamic acid most 

 readily transfers its amino group to a-keto acids forming new amino 

 acids. Krebs and Cohen (1939) described the formation of glutamic 

 acid together with succinic acid oxidatively from ammonium salts and 

 a-ketoglutaric acid. 



Green, et al. (1943) and Blanchard, et al. (1944) obtained highly 

 active enzyme preparations from the kidney of rabbit, cat, mouse and 

 pig which catalyzed the oxidation of the following twelve amino acids 

 to the corresponding a-keto acids. Given in the descending order of 

 oxidation velocities, these amino acids are: leucine, methionine, nor- 

 leucine, norvaline, phenylalanine, tryptophane, isoleucine, tyrosine, 

 cystine and valine, histidine (oxidative splitting of the ring) and 

 alanine. It had little, if any, action on aspartic acid, glutamic acid, 

 arginine, ornithine, lysine, serine and threonine, and no action on P- 

 alanine, glycine or d-amino acids. Green, et al. (1944) and Blanchard, 

 et al. (1945) showed that 1-amino acid oxidase isolated from rat kidney 

 is a flavoprotein which oxidizes both dihydrocozymase I and 1-amino 

 acids. This flavoprotein contains flavinmonophosphate as prosthetic 

 group which is not identical with flavin adenine dinucleotide. 



Bemheim, et al. (1935) and Stumpf and Green (1944) reported 

 that suspensions of young cultures of Proteus vulgaris oxidize practi- 

 cally all the known natural amino acids in the following manner: 



RCHNHoCOOH-t-V^Og^RCOCOOH-l-NHg-fH.O 



Suspensions of cells which were kept at 0° for two weeks lost part of 

 their activity and were capable of oxidizing only eleven of the 22 amino 

 acids which were attacked originally. It was, therefore, concluded that 

 there are at least several enzymes which are involved in the oxidation 

 of 22 amino acids by young suspensions of this organism. 



Cell-free extracts prepared from Proteus vulgaris (Stumpf and 

 Green, 1944), like the aged suspensions of whole cells, were found 

 to be incapable of oxidizing dl-serine, 1-aspartic acid, 1-glutamic acid, 

 dl-alanine, dl-valine, 1-proline, dl-threonine, 1-ornithine, 1-lysine, and 



