The fate of the carboxyl oxygens during D-proline reduction by clostridial proline reductase.
D-Proline is converted to 5-amino valeric acid by D-proline reductase. This conversion involves the reductive cleavage of the alpha-carbon-nitrogen bond. We have examined the fate of the carboxyl oxygen atoms during conversion of D-proline to delta-NH2-valeric acid. 18O atoms from the carboxyl group of D-proline are not lost during conversion to product. In contrast, in the conversion of glycine to acetyl phosphate by glycine reductase a carboxyl oxygen atom is lost to solvent. An intermediate acyl-enzyme is found during the reduction of glycine. We conclude that the reduction of proline proceeds without the formation of an acyl enzyme intermediate.
Arkowitz
R A
RA
MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
Dhe-Paganon
S
S
Abeles
R H
RH
D000594:Amino Acid Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D003013:Clostridium / Q000201:enzymology*; D007553:Isotope Labeling / Q000379:methods; D013058:Mass Spectrometry; D009097:Multienzyme Complexes / Q000378:metabolism; D010103:Oxygen Isotopes; D011392:Proline / Q000737:chemistry / Q000378:metabolism*; D012997:Solvents; D013237:Stereoisomerism; D013379:Substrate Specificity
D009097:Multienzyme Complexes; D010103:Oxygen Isotopes; D012997:Solvents; D011392:Proline; C022452:D-proline reductase (dithiol); D000594:Amino Acid Oxidoreductases; C020815:glycine reductase