Laboratory of Biotransformation, Institute of Microbiology of the Academy of Science of the Czech Republic, 142 20 Prague, Czech Republic.
Curr Opin Chem Biol. 2010 Apr;14(2):130-7. doi: 10.1016/j.cbpa.2009.11.018. Epub 2010 Jan 18.
The range of possible nitrilase applications has been recently broadened but in most cases the parameters of the reactions need to be improved to establish viable industrial processes. To achieve this goal, several methods have been used, primarily in screening for enzymes from new sources, enzyme improvement, substrate structure modification, medium engineering, and variation in process parameters. New nitrilases have been obtained by for example genome mining and the metagenomic approach. Protein engineering revealed targets for altering substrate specificity, activity or enantioselectivity, and for changing the acid:amide ratio in the nitrilase product. Variation in substrate structure proved to be another means to modify the enantioselectivity and chemoselectivity of the reactions. The utility of nitrilases will be increased further if they can be applied in combination with other enzymes or chemical catalysts without laborious intermediate isolation. Such processes have been developed, for instance, for the synthesis of (S)-mandelic acid, (S)-mandeloamide or glycolic acid.
近年来，腈水解酶的应用范围不断扩大，但在大多数情况下，需要改进反应参数，以建立可行的工业工艺。为了实现这一目标，已经使用了几种方法，主要是在筛选新来源的酶、酶的改进、底物结构修饰、培养基工程以及工艺参数的变化方面。例如，通过基因组挖掘和宏基因组方法已经获得了新的腈水解酶。蛋白质工程揭示了改变底物特异性、活性或对映选择性的目标，并改变了腈水解酶产物中的酸：酰胺比例。改变底物结构被证明是另一种方法，可以改变反应的对映选择性和化学选择性。如果腈水解酶可以与其他酶或化学催化剂结合使用，而无需繁琐的中间分离，它们的用途将会进一步增加。例如，已经开发了用于合成（S）-扁桃酸、（S）-扁桃酰胺或乙醇酸的此类工艺。
