title: Effects of Site-specific Mutagenesis of K253 and N184V on the Thermostability of D-Glucose Isomerase.
abstract: In order to enhance the thermostability of D-Glucose isomerase (GI), its mutants, GIK253R and GIN184V, were obtained with the double primer method of site-directed mutagenesis. Then their biochemical properties were assayed and compared with wild-type GI. The results showed that: (1) The mutant K253R was less stable than the wild-type GI at 70 degrees and 80 degrees. But in 1 M L-Rhaminose at 70 degrees, they had similar rate of heat inactivation. Furthermore, the mutant K253R has higher specific activity than the wild-type GI. (2) The mutant N184V had much less thermostability and specific activity as compared with the wild-type GI. These results were explained by their kinetic parameters and crystal structure model.
authors.affiliation: Department of Biology, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Chuan-Jin
authors.initials: CJ
authors.lastname: Wu
authors.forename: Ya-Zhong
authors.initials: YZ
authors.lastname: Xiao
authors.forename: Fan
authors.initials: F
authors.lastname: Long
authors.forename: Mai-Kun
authors.initials: MK
authors.lastname: Teng
authors.forename: Chun
authors.initials: C
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Cui