FIG. 4.

Effect of Na⁺ on the NADH-induced formation of organic radicals by the membrane-bound Na⁺-NQR. Membranes from the wild-type V. cholerae strain were reduced with 7.3 mM NADH in the presence of 0.08 mM Na⁺ (gray trace) or 14.7 mM Na⁺ (black trace). For EPR conditions, see the legend to Fig. 3.