title: On the thermodynamic equilibrium between (R)-2-hydroxyacyl-CoA and 2-enoyl-CoA.
abstract: A combined experimental and computational approach has been applied to investigate the equilibria between several alpha-hydroxyacyl-CoA compounds and their 2-enoyl-CoA derivatives. In contrast to those of their beta, gamma and delta counterparts, the equilibria for the alpha-compounds are relatively poorly characterized, but qualitatively they appear to be unusually sensitive to substituents. Using a variety of techniques, we have succeeded in measuring the equilibrium constants for the reactions beginning from 2-hydroxyglutaryl-CoA and lactyl-CoA. A complementary computational evaluation of the equilibrium constants shows quantitative agreement with the measured values. By examining the computational results, we arrive at an explanation of the substituent sensitivity and provide a prediction for the, as yet unmeasured, equilibrium involving 2-hydroxyisocaproyl-CoA.
authors.affiliation: Laboratory for Microbiology, Philipps-Universität, Marburg, Germany.
authors.forename: Anutthaman
authors.initials: A
authors.lastname: Parthasarathy
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Buckel
authors.forename: David M
authors.initials: DM
authors.lastname: Smith
mesh_terms: D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D002845:Chromatography / Q000379:methods; D003065:Coenzyme A / Q000737:chemistry*; D015256:Coenzyme A-Transferases / Q000737:chemistry; D004583:Electrons; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D008958:Models, Molecular; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013053:Spectrophotometry / Q000379:methods; D013816:Thermodynamics
chemical_list: D002244:Carbon; D015256:Coenzyme A-Transferases; C032430:glutaconate CoA-transferase; D003065:Coenzyme A