Coproporphyrinogenase activity in extracts from rhodopseudomonas spheroides

Induction of Porphyrin Synthesis in Etiolated Bean Leaves by Chelators of Iron

“…The following observations support the catalytic role of iron in the conversion of copro to proto: (a) Iron chelators such as o-phenanthroline and a,a'-dipyridyl inhibit cell extracts which can catalyze the conversion of coprogen to proto (50,53); (b) addition of iron to suspensions of photosynthetic bacteria (10,31,36) or to tobacco leaf discs (27), both of which are irondeficient, lowers their capacity to form copro from exogenous substrates and increases the production of bchl by the bacteria or proto by the leaf tissue. (c) a mutant of tomato exists which, if cultured in a medium which renders iron unavailable to the plant, will form copro from exogenous substrates but, if iron is made available to the plant by changing the culture medium, the mutant produces a normal phenotype and will synthesize considerably more proto and Chl from substrates while producing less copro (39).…”

“…was vacuum-filtered through an asbestos-coated funnel, and the residue was resuspended volume of the extraction solution and filtrates were combined and the residue, fluorescent, was discarded. The combined with an equal volume of petroleum ether [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58] to remove Crystalline standards of copro and proto methyl esters were hydrolyzed in 3 N HCl for 12 hr. This yielded a mixture of partial esters as chromatographic standards (20).…”

“…Vol. 53,1974 Mg proto (ME) (1, 10, 11, 17-20, 28, 47). An additional absorption peak at 471 nm is present in the eluate containing component II.…”

Anaerobic protoporphyrin biosynthesis does not require incorporation of methyl groups from methionine

“…cells, in reaction mixtures supplemented with Mg 2ϩ and reduced glutathione. Tait (21) showed that anaerobic coproporphyrinogen III oxidation in extracts of Rhodobacter sphaeroides and Chromatium strain D required Mg 2ϩ , ATP, NAD ϩ , and Lmethionine. Similar requirements were reported for anaerobic conversion of coproporphyrinogen III to protoporphyrinogen by extracts of Saccharomyces cerevisiae mitochondria (15).…”

Coproporphyrinogenase activities in extracts of Rhodopseudomonas spheroides

“…By analogy with higher-alkane oxidation (Peterson, Kusunose, Kusunose & Coon, 1967) A crude extract of Rhodopseudomonas spheroides catalyses the conversion of coproporphyrinogen into protoporphyrin when incubated aerobically or anaerobically (Tait, 1969). Under anaerobic conditions there is no conversion unless MgSO4, L-methionine and ATP are added.…”