Effect of residue Y76 on co-enzyme specificity of meso-diaminopimelate dehydrogenase from Symbiobacterium thermophilum.
- Author:
Leiming ZHAO
;
Weidong LIU
;
Xi CHEN
;
Min WANG
;
Jinhui FENG
;
Qiaqing WU
;
Dunming ZHU
- Publication Type:Journal Article
- MeSH:
Amino Acid Oxidoreductases;
chemistry;
Amino Acids;
Clostridiales;
enzymology;
Mutation;
NAD;
NADP;
Substrate Specificity
- From:
Chinese Journal of Biotechnology
2015;31(7):1108-1118
- CountryChina
- Language:Chinese
-
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.
