Fig 10. Effect of protein synthesis inhibitors on the activation of respiration by K⁺.

Thawed CyoB^-/CcoN^- K⁺-depleted cells (10⁹/ml) grown on malate were incubated with either 4.2 μl of ethanol (solvent effect control), 30 μg/ml of chloramphenicol or 12.5 μg/ml of tetracycline for 9 min before addition of 16.5 mM sodium malate, followed 4 min later by 5 mM KCl. The respiration rates observed during incubation with sodium malate only (red) and after KCl addition were averaged for five independent experiments for each condition. Error bars correspond to S.E. The slight inhibition of the K⁺ activated respiration by chloramphenicol (11%) and tetracycline (15%) relative to the no inhibitor condition was statistically significant (p<0.05; t-test).