title: Investigation of asymmetric alcohol dehydrogenase (ADH) reduction of acetophenone derivatives: effect of charge density.
abstract: In an effort to study the effect of substituent groups of the substrate on the alcohol dehydrogenase (ADH) reductions of aryl-alkyl ketones, several derivatives of acetophenone have been evaluated against ADHs from Lactobacillus brevis (LB) and Thermoanaerobacter sp. (T). Interestingly, ketones with non-demanding (neutral) para-substituents were reduced to secondary alcohols by these enzymes in enantiomerically pure form whereas those with demanding (ionizable) substituents could not be reduced. The effect of substrate size, their solubility in the reaction medium, electron donating and withdrawing properties of the ligand and also the electronic charge density distribution on the substrate molecules have been studied and discussed in detail. From the results, it is observed that the electronic charge distribution in the substrate molecules is influencing the orientation of the substrate in the active site of the enzyme and hence the ability to reduce the substrate.
authors.affiliation: Technische Universiteit Eindhoven, Laboratory of Polymer Chemistry, Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven, The Netherlands. h.g.naik@tue.nl
authors.forename: Hemantkumar G
authors.initials: HG
authors.lastname: Naik
authors.forename: Bahar
authors.initials: B
authors.lastname: Yeniad
authors.forename: Cor E
authors.initials: CE
authors.lastname: Koning
authors.forename: Andreas
authors.initials: A
authors.lastname: Heise
mesh_terms: D000098:Acetophenones / Q000737:chemistry* / Q000378:metabolism; D000426:Alcohol Dehydrogenase / Q000378:metabolism*; D052196:Levilactobacillus brevis / Q000201:enzymology*; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D055672:Static Electricity; D013237:Stereoisomerism; D013379:Substrate Specificity; D046968:Thermoanaerobacter / Q000201:enzymology*
chemical_list: D000098:Acetophenones; D000426:Alcohol Dehydrogenase; C038699:acetophenone