FIGURE 7.

Relationship between the observed rate of H₂O₂ production by the BCKDH complex and the reduction state of NAD(P)H. A, dependence of the rate of H₂O₂ production on KMV concentration in non-phosphorylating medium after the addition of 4 μm rotenone. B, dependence of %NAD(P)H reduction on 3-methyl-2-oxopentanoate concentration in non-phosphorylating medium after the addition of rotenone (100% reduction was subsequently established by the addition of 5 mm malate and glutamate). C, relationship between the observed rate of H₂O₂ production from the BCKDH complex (plus site I_F) and NAD(P)H reduction state (filled squares) obtained by combining panels A and B; the open symbols are the replotted data for site I_F alone from Fig. 2D. Where not visible, error bars are contained within the points. Data are the means ± S.E. (n = 4).