Cloning and characterization of a novel carbonyl reductase for asymmetric reduction of bulky diaryl ketones
不对称还原大位阻二芳香基甲酮的羰基还原酶的基因克隆及性质分析

Asymmetric reduction of bulky diaryl ketones is still one of the challenging tasks in biocatalysis. By genomic data mining, a putative carbonyl reductase gene pascr was found in Pichia pastoris GS115. pascr was cloned and over-expressed in Escherichia coli Rosseta2 (DE3). The recombinant enzyme was purified to homogeneity by Ni-NTA column and its catalytic properties were studied. PasCR strictly used NADPH as cofactor, gel filtration and SDS-PAGE analysis suggested that the native form of PasCR was a dimmer. PasCR exhibited the highest activity at 35 °C in phosphate buffer at pH 6.5. The enzyme catalyzed the reduction of some bulky diaryl ketones, such as 4-methylbenzophenone, 2-methylbenzophenone and 4-chlorobenzophenone, especially for 4-methylbenzophenone, the product S - alcohol was obtained with 85% ee.