title: [Effect of residue Y76 on co-enzyme specificity of meso-diaminopimelate dehydrogenase from Symbiobacterium thermophilum].
abstract: In industrial application of NAD(P)H-dependent dehydrogenases, NAD(H) has the advantages over NADP(H) in higher stability, lower price and wider recycling system. Recently, a meso-2,6-diaminopimelate dehydrogenase from Symbiobacterium thermophilum (StDAPDH) has been found to be a useful biocatalyst for the production of D-amino acids, but it requires NADP(H) as co-enzyme. To switch the co-enzyme specificity from NADP(H) to NAD(H), we studied the effect of Y76 on the co-enzyme specificity of StDAPDH, because the crystal structural analysis indicated that residue Y76 is near the adenine ring. The mutation of Y76 exerted significant effect on the co-enzyme specificity. Furthermore, the double mutant R35S/R36V significantly lowered the specific activity toward NADP+, and the combination of R35S/R36V with some of the Y76 mutants resulted in mutant enzymes favorable NAD+ over NADP+. This study should provide useful guidance for the further development of highly active NAD(+)-dependent StDAPDH by enzyme engineering.
authors.forename: Leiming
authors.initials: L
authors.lastname: Zhao
authors.forename: Weidong
authors.initials: W
authors.lastname: Liu
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Jinhui
authors.initials: J
authors.lastname: Feng
authors.forename: Qiaqing
authors.initials: Q
authors.lastname: Wu
authors.forename: Dunming
authors.initials: D
authors.lastname: Zhu
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000737:chemistry*; D000596:Amino Acids; D000068016:Eubacteriales / Q000201:enzymology*; D009154:Mutation; D009243:NAD; D009249:NADP; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D009243:NAD; D009249:NADP; D000594:Amino Acid Oxidoreductases; C020032:diaminopimelate dehydrogenase