Fig 2.

Inhibition of NADH-dependent respiration. H. halophilus was grown in NB-Mg²⁺medium in the presence of 1.0 M NaCl to the exponential growth phase (OD₅₇₈ of about 0.6 to 0.8). After harvesting and washing the cells, membranes were isolated. One hundred microliters of the membranes (protein concentration, 32 mg/ml) was incubated in 2.9 ml buffer (50 mM Tris, 50 mM MgSO₄, pH 7.8) containing HDQ (A), antimycin A (B), KCN (C), or ZnCl₂ in the concentrations indicated.