ENERGY-LINKED REACTIONS IN PHOTOSYNTHETIC BACTERIA, V. RELATION OF THE LIGHT-INDUCED PROTON UPTAKE TO PHOTOPHOSPHORYLATION IN R. rubrum CHROMATOPHORES^*

Abstract

The kinetics of photophosphorylation have been studied in Rhodospirillum rubrum chromatophores. No evidence for a time or intensity lag in photophosphorylation was found. An intensity lag could be induced with the uncoupling agent, m-chlorocarbonyl cyanide phenylhydrazone or, in some cases, by aging of the chromatophores.

In chloroplasts, the occurrence of a time and intensity lag in phosphorylation has been correlated with the formation of a proton gradient and quoted as evidence that a proton gradient is a prerequisite of phosphorylation. The significance of the absence of a time and intensity lag in chromatophores is discussed in this context.