Enhancing the α-Cyclodextrin Specificity of Cyclodextrin Glycosyltransferase from Paenibacillus macerans by Mutagenesis Masking Subsite -7.

ABSTRACT: Cyclodextrin glycosyltransferases (CGTases) (EC 2.4.1.19) catalyze the conversion of starch or starch derivates into mixtures of α-, β-, and γ-cyclodextrins. Because time-consuming and expensive purification procedures hinder the widespread application of single-ingredient cyclodextrins, enzymes with enhanced specificity are needed. In this study, we tested the hypothesis that the α-cyclodextrin selectivity of Paenibacillus macerans α-CGTase could be augmented by masking subsite -7 of the active site, blocking the formation of larger cyclodextrins, particularly β-cyclodextrin. Five single mutants and three double mutants designed to remove hydrogen-bonding interactions between the enzyme and substrate at subsite -7 were constructed and characterized in detail. Although the rates of α-cyclo

SUBMITTER: Wang L 

PROVIDER: S-EPMC4959485 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature