Excessive urinary excretion of methionine in mutant mice lacking D-amino-acid oxidase activity.
Thin-layer chromatography and amino acid analysis showed that mutant (ddY/DAO-) mice lacking D-amino-acid oxidase activity excreted about 3.5 times more methionine in urine than did normal (ddY/DAO+) mice. High-performance liquid chromatography using a chiral column showed that approximately 82% of urinary methionine of the ddY/DAO- mice had the D-configuration. Analysis revealed that the mouse diet used contained 0.04% free methionine and that approximately 46% of methionine was the D-isomer. When the ddY/DAO- mice were given a diet containing a low level of supplementary DL-methionine or a diet without D-methionine, they excreted the normal levels of methionine. These results indicate that the ddY/DAO- mice were unable to metabolize D-methionine and excrete it in urine.
D000596:Amino Acids / Q000652:urine; D000818:Animals; D002855:Chromatography, Thin Layer; D003605:D-Amino-Acid Oxidase / Q000172:deficiency*; D004032:Diet; D008715:Methionine / Q000008:administration & dosage / Q000652:urine*; D051379:Mice; D008817:Mice, Mutant Strains
D000596:Amino Acids; D008715:Methionine; D003605:D-Amino-Acid Oxidase