Oxidative Phosphorylation in Fractionated Bacterial Systems: Effect of Chloramphenicol

Abstract

Chloramphenicol was found to have a direct effect on the respiratory chain of Mycobacterium phlei cells grown in the presence of this drug. Analysis of the respiratory chain components revealed that the presence of chloramphenicol during growth resulted in a partial inhibition in the synthesis of the cytochromes. However, a stimulation in oxidative phosphorylation was observed with the cell-free extract of cells grown in the presence of chloramphenicol. The oxidation of succinate was found to be stimulated 20 to 130%, depending on the particular extract, whereas the oxidation of reduced nicotinamide adenine dinucleotide (NADH) was found to be similar to that of extracts obtained from cells grown in the absence of the drug. Of particular interest was the finding that the cell-free extract of cells grown in the presence of the drug exhibited an increased level of phosphorylation (17 to 100%) when NADH was used as the electron donor. Chloramphenicol appears to affect a component of the respiratory chain between the flavoprotein and cytochrome c . Fractionation of the electron transport particles revealed an increased level of cytochrome b in the fractions which exhibited a stimulation in oxidative phosphorylation.