A disulfide photoreduction system in chromatophores of Rhodospirillum rubrum.

Chromatophores isolated from photosynthetic bacteria contain a disulfide-bonded repeating antigenic substructure that is serologically specific and present on the cell particles only during photosynthetic growth (l-3). This finding suggests that the structural antigen may also be a functional part of the photosynthetic electron transport system. This suggestion has been explored and supported by studies on the inhibition of photophosphorylation by disulfide exchange and scission reactions (4). The present communication describes the existence in Rhodospirillum rubrum chromatophores of a photochemical disulfide reducing system, and reports some properties of this system.