Figure 3.

Progress curves of [NADH] versus time for forward reaction (direction of NAD reduction) at various pH values without product inhibitors present in initial buffer. Initial conditions are [NAD]₀ = 1 mM and (A) [MAL]₀ = 10 mM, pH 6.5; (B) [MAL]₀ = 20 mM, pH 6.5; (C) [MAL]₀ = 5 mM, pH 7.0; (D) [MAL]₀ = 10 mM, pH 7.0; (E) [MAL]₀ = 5 mM, pH 7.5; (F) [MAL]₀ = 10 mM, pH 7.5; (G) [MAL]₀ = 1 mM, pH 8.0; (H) [MAL]₀ = 2 mM, pH 8.0; (I) [MAL]₀ = 1 mM, pH 8.5; (J) [MAL]₀ = 2 mM, pH 8.5; (K) [MAL]₀ = 0.5 mM, pH 9.0; and (L) [MAL]₀ = 1 mM, pH 9.0. (In each plot the shaded lines and solid lines, respectively, represent mean with standard deviation of experimentally measured [NADH], and [NADH] obtained from fitting data to ordered bi-bi mechanism.)