Rizzi M, Stylos P, Riek A, Reuss M
Institut für Bioverfahrenstechnik, Universität Stuttgart, Germany.
Enzyme Microb Technol. 1992 Sep;14(9):709-14. doi: 10.1016/0141-0229(92)90110-a.
Isoamyl acetate was synthesized by lipase-catalyzed transesterification of ethyl acetate in n-hexane. The selectivity and rates of ester formation decreased when water content of the immobilized enzyme exceeded 3% (w/w). Experimental observations clearly indicate that the substrates as well as the product (ethanol) act as dead-end inhibitors. A ping-pong bi-bi mechanism with competitive inhibition by substrates and products is proposed that predicts the experimental observation satisfactorily.
通过脂肪酶催化乙酸乙酯在正己烷中的酯交换反应合成了乙酸异戊酯。当固定化酶的含水量超过3%(w/w)时,酯形成的选择性和速率降低。实验观察清楚地表明,底物以及产物(乙醇)起终产物抑制剂的作用。提出了一种底物和产物具有竞争性抑制作用的乒乓双底物机制,该机制能令人满意地预测实验观察结果。