Table 1. Effect of nicornadil on enzyme kinetic parameters.
Enzyme | h | kcat * × 10-6 (s-1) | KM (nM) | kcat/KM (s-1) | Fold-increase# |
---|---|---|---|---|---|
Wild-type | 1.0 | 0.77 +/- 0.038 | 15 +/- 3 | 5.1 × 104 | |
Wild-type + nicorandil | 1.7 | 1.1 +/- 0.046 | 13 +/- 1 | 9 × 104 | 1.7 |
R177A | 1.0 | 5.4 +/- 0.034 | 28 +/- 6 | 19 × 104 | 3.8 |
R177A + nicorandil | 1.2 | 9.1 +/- 0.40 | 14 +/- 2 | 67 × 104 | 3.4 |
h refers to the Hill slope calculated for an allosteric sigmoidal kinetics model in GraphPad.
kcat values are divided by 106 and were calculated as Vmax/[enzyme (nM)]. Vmax is in relative fluorescence units per second. Active enzyme concentration was estimated as the total enzyme concentration in this case.
# Fold increase is reported for wild-type stimulated by nicorandil vs. wild-type alone, R177A vs. wild-type, and R177A stimulated by nicroandil vs. R177A APE1 alone.