Phenylalanine ammonia lyase in the management of phenylketonuria: the relationship between ingested cinnamate and urinary hippurate in humans.
The hypothesis that the action of an oral preparation of the enzyme phenylalanine ammonia lyase, used to lower blood phenylalanine levels in phenylketonuria, is by removal of phenylalanine from hydrolysed protein in the lumen of the gut has been examined. Phenylalanine ammonia lyase mediates the conversion of phenylalanine to cinnamate. If cinnamate is produced in the gut it will be absorbed and converted to hippurate in the liver. However, treatment with phenylalanine ammonia lyase does not result in raised urinary hippurate ammonia lyase does not result in raised urinary hippurate levels while ingestion of cinnamate does.
D000293:Adolescent; D000328:Adult; D000642:Ammonia-Lyases / Q000494:pharmacology*; D002934:Cinnamates / Q000378:metabolism*; D004032:Diet; D004044:Dietary Proteins / Q000494:pharmacology; D006626:Hippurates / Q000652:urine*; D006801:Humans; D008875:Middle Aged; D010649:Phenylalanine / Q000097:blood; D010650:Phenylalanine Ammonia-Lyase / Q000494:pharmacology*; D010661:Phenylketonurias / Q000652:urine*
D002934:Cinnamates; D004044:Dietary Proteins; D006626:Hippurates; D010649:Phenylalanine; D000642:Ammonia-Lyases; D010650:Phenylalanine Ammonia-Lyase; C030514:hippuric acid