Skip to main content
Article thumbnail
Location of Repository

Reduction of iron and synthesis of protoheme by Spirillum itersonii and other organisms.

By H A Dailey and J Lascelles

Abstract

Membranes from Spirillum itersonii reduce ferric iron to ferrous iron with reduced nicotinamide adenine dinucleotide or succinate as a source of reductant. Iron reduction was measured spectrophotometrically at 562 nm using ferrozine, which chelates ferrous iron specifically. Reduced nicotinamide adenine dinucleotide or succinate was also effective as a source of iron. The effects of respiratory inhibitors suggested that reduction of iron occurs at one or more sites on the respiratory chain before cytochrome c. Reduction of iron and synthesis of protoheme with the physiological reductants were also observed with crude extracts of other bacteria, including Rhodopseudomonas spheroides, Rhodopseudomonas capsulata, Paracoccus denitrificans, and Escherichia coli. The effect of oxygen upon reduction of iron and formation of protoheme was examined with membranes from S. itersonii, using succinate as a source of reductant. Both systems were inhibited by oxygen, but this effect was completely reversed by addition of antimycin A. We conclude that reduced components of the respiratory chain serve as reductants for ferric iron, but with oxygen present they are oxidized preferentially by the successive members of the chain. This could be a mechanism for regulating synthesis of heme and cytochrome by oxygen

Topics: Research Article
Year: 1977
OAI identifier: oai:pubmedcentral.nih.gov:235016
Provided by: PubMed Central
Sorry, our data provider has not provided any external links therefore we are unable to provide a link to the full text.

Suggested articles


To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.