Reactive iron species in biological fluids activate the iron-sulphur cluster of aconitase.
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.
Mumby
S
S
Department of AICU, Royal Brompton Hospital, National Heart and Lung Institute, Imperial College of Science Technology and Medicine, London, UK.
Koizumi
M
M
Taniguchi
N
N
Gutteridge
J M
JM
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
D000903:Antibiotics, Antineoplastic; D007202:Indicators and Reagents; D007506:Iron-Sulfur Proteins; D008024:Ligands; D001761:Bleomycin; D007501:Iron; D000154:Aconitate Hydratase; D001205:Ascorbic Acid