화학공학소재연구정보센터
Biotechnology Letters, Vol.34, No.2, 339-346, 2012
Enhancement of pH stability and activity of glycerol dehydratase from Klebsiella pneumoniae by rational design
Glycerol dehydratase (GDHt) is a key and rate-limiting enzyme in the pathway of 1,3-propanediol (1,3-PD) synthesis. The improvement of GDHt's stability and enzymatic activity is desirable for the biosynthesis of 1,3-PD. The gldABC gene encoding GDHt of Klebsiella pneumoniae was cloned and expressed in Escherichia coli XL10-Gold, and the mutation sites of GDHt were obtained through prediction by PoPMuSiC program. Consequently, two mutants (KpG60 and KpG525) were developed by rational design through site-mutagenesis based on 3D structure which was constructed from homology modeling. Analyses of enzymatic properties showed that pH stability of the mutants was about 1.25-2 times higher than that of the wild type, and specific activity, V(max) and K(cat)/K(m) of KpG525 were about 1.5-2 times higher than those of the wild type. This work presented a simple and useful measure to improve the performance of industrial enzyme.