P504s / AMACR a-methyl-CoA Racemase is an essential enzyme in the b-oxidation of branched-chain fatty acids, it is responsible for the conversion of pristanoyl-CoA and C27-bile acyl-CoAs to their (S)-stereoisomers, which are the only stereoisomers that can be degraded via peroxisomal beta-oxidation. High expression of P504s protein is found in prostatic adenocarcinoma but not in benign prostate tissue by immunohistochemical staining in paraffin-ebmbedded tissue. The expression of P504s is also detected in two premalignant lesions of the prostate: high-grade prostatic intraepithelial neoplasia (PIN) and atypical adenomatous hyperplasia Synonyms: Alpha-methylacyl-CoA racemase, EC 5.1.99.4, 2-methylacyl-CoA racemase, AMACR, RACE, P504s