N-acetyl glucosamine isomerase mutant and application thereof

The invention provides an N-acetyl glucosamine isomerase mutant and application of the N-acetyl glucosamine isomerase mutant. The N-acetyl glucosamine isomerase mutant is obtained by carrying out mutation on any one or more sites of glutamic acid at the 73rd site, glutamine at the 110th site, leucine at the 171st site, alanine at the 172nd site and alanine at the 198th site of wild type N-acetyl glucosamine isomerase. Compared with wild type N-acetyl glucosamine isomerase, the N-acetyl glucosamine isomerase mutant constructed by the invention has higher catalytic activity, and the enzymatic activity of the N-acetyl glucosamine isomerase mutant is improved by 27-55%. The modified N-acetylglucosamine isomerase mutant disclosed by the invention can be better applied to preparation of N-acetylneuraminic acid, and is more suitable for industrial application. 本发明提供了一种N-乙酰葡萄糖胺异构酶突变体及其应用。所述的N-乙酰葡萄糖胺异构酶突变体，是对野生型N-乙酰葡萄糖胺异构酶位于第73位谷氨酸、第110位谷氨酰胺、第171位亮氨酸、第172位丙氨酸或第198位丙氨酸中的任意一个或几个位点进行突变得到的。与野生型N-乙酰葡萄糖胺异构酶相比，本发明所构建的N-乙酰葡萄糖