Abstract
1. 1. d-Amino acid oxidase (d-AAO) oxidizes: d-Met, d-Pro, d-Phe, d-Tyr, d-Ile, d-Leu, d-Ala and d-Val. d-Ser, d-Arg, d-His, d-norleucine and d-Trp are oxidized at a low rate. d-Ornithine, cis-4-hydroxy-d-proline, d-Thr, d-Trp-methyl ester, N-acetyl-d-Ala and d-Lys are oxidized at a very low rate. 2. 2. d-Asp, d-Glu and their derivatives, Gly and all the l-amino acids are not oxidized (or are at a rate which is undetectable). 3. 3. Among all d-amino acids, d-Met is the most highly oxidized compound. The Km value is 1.7 mM. 4. 4. d-Aspartate oxidase (d-Aspo) either purified from Octopus vulgaris or from beef kidney oxidizes only d-Asp, d-Glu and their following derivatives: d-Asn, d-Gln, d-Asp-dimethyl-ester and N-methyl-d-Asp. 5. 5. However, d-Pro, d-Leu, d-Ala and d-Met, are also oxidized by this enzyme, but at a very low rate (between 0.2 and 0.6% of d-Asp). 6. 6. All other d-amino acids, glycine and all the l-amino acids are not oxidized. 7. 7. Under experimental conditions, 1 U of d-AAO is able to totally oxidize 0.1 μmol of the following amino acids: d-Met, d-Pro, d-Phe, d-Thy, d-Ile, d-Leu, d-Ala, d-Val, d-Ser and d-Arg. 8. 8. Similarly, 1 U of d-AspO in 1 hr of incubation totally oxidizes 0.1 μmol of d-Asp, d-Glu, d-Asn and d-Gln. © 1993.