title: NADP+ production using thermostable NAD+ kinase of corynebacterium flaccumfaciens AHU-1622.
abstract: A sonicate of Corynebacterium flaccumfaciens AHU-1622 had the highest NAD+ kinase activity (1.22 mU/mL culture broth) of the strains of bacteria we investigated. This enzyme was thermostable, with activity maintained at 50 degrees C for 1 h. This treatment inactivated phosphatase activity. Resting cells of the bacterium also had NAD+ kinase activity when treated at 60 degrees C for 30 min with 0.2% Triton X-100. NADP+ production was achieved using 8 mumol NAD+, 8 mumol ATP, 16 mumol MgCl2, 1.6 mumol NaN3, and 12 mU NAD+ kinase (0.1 g of permeabilized wet cells) in 2 mL of 0.1 M phosphate buffer, pH 7.5. The conversion ratio of NADP+ from NAD+ was 75% after 10 h of incubation at 50 degrees C, and the amount of accumulated NADP+ was 3 mumol/mL of reaction mixture. The NAD+ kinase activity of the permeabilized cells was stable and did not decrease after repeated use.
mesh_terms: D003352:Corynebacterium / Q000201:enzymology*; D004355:Drug Stability; D005285:Fermentation; D006358:Hot Temperature; D007700:Kinetics; D009249:NADP / Q000096:biosynthesis*; D010770:Phosphotransferases / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor); D013045:Species Specificity
chemical_list: D009249:NADP; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C021844:NAD kinase