Purification and identification of two carnosine-cleaving enzymes, carnosine dipeptidase I and Xaa-methyl-His dipeptidase, from Japanese eel (Anguilla japonica)

► A narrow substrate-specific enzyme encoded by CNDP1 is identified from eel muscle. ► Eel liver strongly expresses CNDP1. ► CNDP1 is not detected in other ray-finned fishes except eel and salmonid species.