... PTDH, and an Arg replaced Ala176 to stabilize the additional negative charge of NADP PTDH-E17 5A A1 76R displayed relaxed cofactor specicity with a Km for NADP that is decreased over 700-fold compared ... Table Kinetic comparison of WT and Mutant PTDH and FDH with either NADP or NAD Enzyme (cofactor) KM NADP (lM) kcat (min)1) kcat KM, WT PTDH (NAD )a WT PTDH (NADP )a E17 5A A1 76R (NAD )a E17 5A A1 76R ... constant of NADPH (KIS), a matrix of 25 assays was carried out utilizing ve varying concentrations of NADP (300, 30, 10, 4.8, and lm) and ve varying concentrations of NADPH (30, 12.5 5, 2, and...