COPROPORPHYRINOGENASE ACTIVITY IN EXTRACTS FROM RHODOPSEUDOMONAS SPHEROIDES

An extract from Rhodopseudomonas spheroides, grown semi-anaerobically in the light, converts coproporph rinogen to protoporphyrin when incubated anaerobically in the dark with Mg2+, ATP and L-methionine. Extracts from R. spheroides grown under air or oxygen in the dark are inactive when assayed under these conditions. Extracts from organisms grown in the light or in the dark form protoporphyrin in the absence of ATP and methionine when incubated with coproporphyrinoren in the presence of oxygen. The anaerobic reaction is inhibited by 1,10-phenanthroline, whilst the aerobic reaction is not. © 1969.