Figure 6

Predictions of OGDHC activity comparing with experimental results. (A) OGDHC activity as a function of free calcium concentration in present of 2.0 mM NAD and 0.25 mM CoASH in the presence of either 1.5 mM ATP (circle) or 1.5 mM ADP (up-triangle). Concentrations of 2-oxoglutarate were 0.05 mM (ADP alone) and 0.1 mM (ATP alone). Kinetic data were obtained from Figure Three of [38]. (B) OGDHC activity as a function of ADP/ATP ratio in the presence of 2.0 mM NAD, 0.25 mM CoASH and 0.05 mM 2-oxoglutarate in the presence of either 1.0 nM (circle) or 1.0 μM (up-triangle) free Ca²⁺. Kinetic data were from Figure Four of [38]. (C) OGDHC activity as a function of NADH/NAD ratio 0.35 mM Mg²⁺ and 0.4 mM total nicotinamide nucleotide in the assay. Ca²⁺ concentration was either 1 nM (circle) or 0.1 mM (up-triangle) and 2-oxoglutarate concentration was 10 mM (circle) or 0.375 mM (up-triangle). Kinetic data were obtained from Figure Five b of [38]. Solid lines are model predictions for the data points represented by symbols. The experimental data were obtained at pH 7.2 and 30°C in reaction medium of 50 mM MOPS, 75 mM KCl, 60 mM sucrose, 2 mM KH₂PO₄, 1 mM EGTA.