title: Properties of nonheme iron in a cell envelope fraction from Escherichia coli.
abstract: The reaction with o-phenanthroline of nonheme iron found in cell envelope fractions from Escherichia coli has been investigated. About 20% of the total nonheme iron reacts directly with o-phenanthroline. This iron appears to be in the ferric state but is reducible by protein sulfhydryl groups in the presence of the chelating agent. A further 20% of the nonheme iron will react with o-phenanthroline only in the presence of dithionite. Succinate can replace dithionite but only produces about 35% of the reaction given by dithionite. The reduction of cytochrome b(1) of the respiratory chain by succinate shows similar behavior to the reaction of iron with o-phenanthroline in the presence of succinate. Both of these components react completely only in the presence of 2-heptyl-4-hydroxyquinoline-N-oxide. The remaining 60% of the nonheme iron of the cell envelope will not react with o-phenanthroline even in the presence of dithionite or 6 m urea. Triton X-100 with dithionite will permit a small part (10%) of this iron to react with o-phenanthroline. The iron which does not react with o-phenanthroline is not associated with succinate, reduced nicotinamide adenine dinucleotide, or d-lactate dehydrogenases.
mesh_terms: D002473:Cell Wall / Q000032:analysis*; D003580:Cytochromes / Q000032:analysis; D004578:Electron Spin Resonance Spectroscopy; D004926:Escherichia coli / Q000032:analysis* / Q000201:enzymology; D005415:Flavins / Q000032:analysis; D007202:Indicators and Reagents; D007501:Iron / Q000032:analysis*; D010618:Phenanthrolines; D011804:Quinolines; D013053:Spectrophotometry; D013385:Succinate Dehydrogenase / Q000032:analysis; D013386:Succinates; D013447:Sulfites; D013501:Surface-Active Agents; D014508:Urea
chemical_list: D003580:Cytochromes; D005415:Flavins; D007202:Indicators and Reagents; D010618:Phenanthrolines; D011804:Quinolines; D013386:Succinates; D013447:Sulfites; D013501:Surface-Active Agents; D014508:Urea; D007501:Iron; D013385:Succinate Dehydrogenase