Some effects of iron deficiency on Rhodopseudomonas spheroides strain Y

Reiss‐Husson, Françoise; Klerk, H. De; G, Jolchine; Jauneau, E.; Kamen, Martin D.

doi:10.1016/0005-2728(71)90132-0

Cited by 24 publications

(9 citation statements)

References 11 publications

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“…Rps spheroides Y was grown photosynthetically in either medium '021' described by Reiss et al [9] in which the iron concentration is 1 pM or in '021 + Fe' in which iron concentration is 17pM. Cells were harvested during late exponential phase, resuspended and washed twice in 0.05 M phosphate buffer pH 7.4 and stored at -15 "C until used.…”

Section: Methodsmentioning

confidence: 99%

5-Aminolevulinic-Acid Synthetases from Rhodopseudomonas spheroides Y. Comparison of the Purification and Properties of Enzymes Extracted from Bacteria Grown in Different Iron Concentrations

Clément‐Métral

Fanica-Gaignier

1975

Eur J Biochem

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The two 5-aminolevulinic acid synthetases of Rhodopseudomonas spheroides Y. were extracted from cells grown in a 'low-iron' medium and purified. They have a specific activity 10-fold higher than the 'high-iron' enzymes described by us previously and have the same properties except that they do not contain any iron and have one free -SH group more per mole of enzyme (2 for E, ; 8 for E2). Their inhibition by adenosine triphosphate and iron and their oxidation-reduction sensitivity are discussed in terms of light, oxygen and heme feed-back regulation of bacteriochlorophyll synthesis.5-Aminolevulinic acid synthetase has been detected in relatively few organisms and only three isolations of pure enzyme have so far been reported [l -31. Some of the most active sources are the photosynthetic bacteria of the Athiorhodacae. Rhodopseudomonas spheroides (Van Niel collection [4] or strain Y [ 5 ] ) contains two different isofunctional enzymes which have been purified to homogeneity and characterized [6,7]. Although the pure 5-aminolevulinic acid synthetases of the mammalian or bacterial sources share in common most of their properties [8], the two enzymes isolated from Rps spheroides Y had a much higher specific activity compared to the others. Two explanations could be discarded: inhomogeneity of the proteins and difference in the assay conditions. A possible explanation for this low specific activity might be that we used a 17 pM iron growth medium whereas in earlier studies of this enzyme, animals (anemic rabbits) or bacteria (grown in an iron-deprived medium) were severely deprived of iron.This work was undertaken to find out if iron, a well-known inhibitor of 5-aminolevulinic acid synthetase, was the cause of the apparent inactivation and to compare the purification and properties of the enzymes grown in high-iron or low-iron medium.

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Section: Methodsmentioning

confidence: 99%

5-Aminolevulinic-Acid Synthetases from Rhodopseudomonas spheroides Y. Comparison of the Purification and Properties of Enzymes Extracted from Bacteria Grown in Different Iron Concentrations

Clément‐Métral

Fanica-Gaignier

1975

Eur J Biochem

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“…spheroides Y was grown anaerobically at 30 "C in 2-1 or 10-1 bottles, with gas stream of N,-C02 (95 -5 %) and a surface illumination of 10 000 lux, as described elsewhere [3]. For "low iron" cultures, the synthetic medium "L" [3] was used (residual iron content : 1 pg-atom/l). For "normal" cultures (that is, not iron-limited) iron was added to medium L before autoclaving to a final concentration of 17 pg-atom/l.…”

Section: Culturesmentioning

confidence: 99%

“…Cell-free extracts were prepared by treatment with a Ribi cell fractionator, as described previously [3]. The supernatant from the centrifugation of the extract at 350000 x g for 2 h was used to isolate the soluble cytochromes.…”

Section: Culturesmentioning

confidence: 99%

“…Determination of the total cellular heme content was performed as described previously [3]. Soluble heme content was determined by the pyridine hemochrome spectrum of the supernatant from centrifuga-I.…”

Section: Quantitative Determination Of Hemoproteinsmentioning

confidence: 99%

“…Recently we have observed that iron deficiency resulted in a severe diminution of the cellular heme content of Rps.spheroides Y [3]. Hence, it was of interest to determine if the various cytochromes were uniformly affected, or if a preferential diminution of some species occurred, hopefully to shed some light on the minimal cytochrome complement essential for photosynthetic growth.…”

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confidence: 99%

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Influence of Iron Deficiency on the Cytochromes of Rhodopseudomonas spheroides

Agalidis

Jauneau

Reiss‐Husson

1974

European Journal of Biochemistry

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Rhodopseudomonas spheroides Y cells were grown photosynthetically in a denned medium supplemented with either a limiting amount of iron or with an excess of iron. Soluble and bound cytochromes were determined in both cases. The composition of the soluble cytochromes was not altered qualitatively by iron deficiency. In both culture conditions, a number of cytochromes were isolated by chromatography and purified to various extents: cytochromes c‐550 (c2 type), c′, c‐551, c‐552, and b‐559. In normal cells cytochrome c2, and to a lesser extent cytochrome c′ predominated whereas the amounts of both were greatly lowered in iron deficiency. Bound cytochromes were detected by difference spectroscopy of particles after chemically or light‐induced oxidoreductions. When iron was not limiting, cells were also grown in presence of diphenylamine, which inhibited carotenoid synthesis and facilitated detection of cytochromes. Particles from those cells, as well as particles from uninhibited cells contained cytochrome c‐551 (bound form of cytochrome c2), cytochrome b‐560, and a minor component, possibly b‐type. All reacted to illumination. In iron‐deficient cells, the bound heme b was almost completely suppressed; difference spectra suggested the presence only of cytochrome c2 and c′.

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