title: Reactive iron species in biological fluids activate the iron-sulphur cluster of aconitase.
abstract: Low molecular mass iron (LMrFe) can appear in plasma when the transferrin becomes fully iron loaded. Such iron poses a risk factor for oxidative damage, and for microbial virulence. A previous novel approach to the detection and measurement of LMrFe in plasma was the use of the iron-binding properties of the glycopeptide antitumour antibiotic bleomycin and its ability to degrade DNA in the presence of oxygen, bound iron, and an iron reducing agent. Since bleomycin is a non-physiological ligand with iron-binding and redox cycling properties, it has been suggested that it may not be a valid biological model for detecting and measuring LMrFe. To address these concerns we have developed a biological approach to the detection and measurement of LMrFe based on the activation of iron-requiring aconitase. Parallel measurements, in a variety of clinical conditions in which there was a complete saturation of the plasma transferrin, showed that the bleomycin assay and the aconitase assay can give similar results for LMrFe.
authors.affiliation: Department of AICU, Royal Brompton Hospital, National Heart and Lung Institute, Imperial College of Science Technology and Medicine, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Mumby
authors.forename: M
authors.initials: M
authors.lastname: Koizumi
authors.forename: N
authors.initials: N
authors.lastname: Taniguchi
authors.forename: J M
authors.initials: JM
authors.lastname: Gutteridge
mesh_terms: D000154:Aconitate Hydratase / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000378:metabolism; D001205:Ascorbic Acid; D001761:Bleomycin / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D007501:Iron / Q000097:blood / Q000737:chemistry / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D010949:Plasma / Q000378:metabolism
chemical_list: D000903:Antibiotics, Antineoplastic; D007202:Indicators and Reagents; D007506:Iron-Sulfur Proteins; D008024:Ligands; D001761:Bleomycin; D007501:Iron; D000154:Aconitate Hydratase; D001205:Ascorbic Acid