Analysis of catalytic properties of quinoprotein glycerol dehydrogenase and its application

藜蛋白甘油脱氢酶（GLDH）是一种在葡萄杆菌中发现的膜结合酶，具有很好的工业应用价值。本研究将GLDH的一级结构与其他藜蛋白进行比较，了解其独特的催化性能，并制备了GLDH突变体，在葡萄球菌中异种表达。这项研究提供了以下发现。(i) PQQ酶的螺旋桨结构，尤其是W1和W2对GLDH活性有重要影响。（ii）在乙酸细菌中构建异源表达体系，制备突变体GLDH。（iii）通过pqq酶间的比较分析，通过点突变制备提高pqq结合稳定性的GLDH突变体。该数据将有助于改善5-酮- d -葡萄糖酸盐等的氧化发酵。

Quinoprotein glycerol dehydrogenase (GLDH) is a membrane-bound enzyme, which is found in Gluconobacter having attractive industrial applications. In this study, the primary structure of GLDH was compared with other quinoproteins to understand its unique catalytic properties, and then mutant GLDH was prepared in heterologous expression in Gluconobacter.This study provided the following finding. (i) The propeller structure of PQQ enzyme, especially W1 and W2, are important for GLDH activity. (ii) Heterologous expression system in acetic acid bacteria was constructed to prepare mutant GLDH (iii) GLDH mutants that improved PQQ-binding stability, were prepared by the point mutation based on comparative analysis among PQQ-enzymes. The data will lead to improvement in oxidative fermentation of 5-keto-D-gluconate and others.