title: Enzymatic formation of D-cysteinolic acid conjugated chenodeoxycholic acid in liver preparation from red seabream, Pagrosomus major.
abstract: The enzymatic formation of D-cysteinolic acid conjugated chenodeoxycholic acid in liver preparation from a marine teleost, wild and cultured red seabream, Pagrosomus major, was investigated. [24-14C]Chenodeoxycholic acid was incubated with taurine, glycine, or D-cysteinolic acid in the liver preparation in the presence of CoA, ATP, NAD+ and FAD. D-Cysteinolic acid could be conjugated efficiently with chenodeoxycholic acid to give chenodeoxycholyl-D-cysteinolic acid in both wild and cultured red seabream liver preparations, though the production rate was slower than that of the formation of chenodeoxycholyltaurine. Under the conditions employed, glycine was not utilized as the substrate for the conjugation at all. The formation of chenodeoxycholyl-D-cystenolic acid was decreased by the addition of various concentrations of taurine to the incubation mixture. These results suggest that bile acid-CoA: amino acid N-acyltransferase in red seabream is not able to distinguish taurine and D-cysteinolic acid as the substrate, probably because of their structural similarity. Consequently, D-cystenolic acid conjugated bile acids found in the bile of wild red seabream were thought to be synthesized in the liver of the fish utilizing the unusual amino acid, which originated from foods, prior to secretion into the bile.
authors.affiliation: Institute of Pharmaceutical Sciences, Hiroshima University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Goto
authors.forename: M
authors.initials: M
authors.lastname: Une
authors.forename: K
authors.initials: K
authors.lastname: Kihira
authors.forename: T
authors.initials: T
authors.lastname: Kuramoto
authors.forename: T
authors.initials: T
authors.lastname: Hoshita
mesh_terms: D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002635:Chenodeoxycholic Acid / Q000378:metabolism*; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism; D005399:Fishes; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D013654:Taurine / Q000378:metabolism
chemical_list: D002635:Chenodeoxycholic Acid; C055419:cysteinolic acid; D013654:Taurine; D000217:Acyltransferases; C026953:bile acid-CoA amino acid N-acyltransferase; D003545:Cysteine