Technische Universiteit Eindhoven, Laboratory of Polymer Chemistry, Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Org Biomol Chem. 2012 Jul 7;10(25):4961-7. doi: 10.1039/c2ob06870b. Epub 2012 May 21.
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.
为了研究底物取代基对醇脱氢酶（ADH）还原芳基-烷基酮的影响，我们评估了几种苯乙酮衍生物对短乳杆菌（LB）和热厌氧菌（T）ADH 的作用。有趣的是，具有非要求（中性）对位取代基的酮被这些酶以对映体纯的形式还原为仲醇，而具有要求（可电离）取代基的酮则不能被还原。我们详细研究和讨论了底物大小、在反应介质中的溶解度、配体的供电子和吸电子性质以及底物分子上的电子电荷密度分布对反应的影响。从结果中可以看出，底物分子中的电子电荷分布影响着底物在酶活性部位的取向，从而影响着底物的还原能力。
