Functional bacterial photoreaction centres with only one type of protein

Abstract

A preparation of purified Rhodospirillum rubrum photoreaction centres was subjected to dialysis under mild denaturing conditions. Sodium dodecyl sulfate—polyacrylamide gel electrophoresis showed that the resulting prepartation contained only one peptidic constituent, apparently the lighter one. The dialyzed centres retained the characteristic absorption spectrum in the visible—near infrared range and actinic light elicited the spectral changes which reflect primary change separation. Thus, it seems that the light protein of the photoreaction centre contains all the binding sites for the primary reactants of bacterial photosynthesis.