In vitro fenoprofenyl-coenzyme A thioester formation: Interespecies variations

SORACI, A.; BENOIT, E

CHIRALITY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 1996 vol. 7 p. 534 - 540

0899-0042

Abstract In vitro coenzyme A thioester formation from (−)-(R)-fenoprofen (FPF) and palmitic acid has been studied using liver microsomes from rat, guinea pig, sheep, and dog. In every species with both palmitic acid or (−)-(R)-fenoprofen, the Lineweaver–Burk plot was linear in the substrate concentration range used and as a consequence agrees with the involvement of only one isoenzyme (or different isoenzymes of similar Km values). The Vmax values for the thioesterification of (−)-(R)-fenoprofen present large species variations from 2.1 ± 1.0 with sheep liver microsomes to 60.6 ± 11 nmol/min/mg with dog liver microsomes. These values statistically significantly correlate (r = 0.94) to the Vmax values observed when palmitic acid was used as a substrate. Furthermore palmitic acid inhibited (−)-(R)-fenoprofen–CoA formation in the same extent in all animal species. The stereoselectivity of the thioesterification was also species dependent. © 1995 Wiley-Liss, Inc.