title: Iron released from transferrin at acidic pH can catalyse the oxidation of low density lipoprotein.
abstract: Low density lipoprotein (LDL) oxidation within the arterial wall may contribute to the disease of atherosclerosis. We have investigated the conditions under which transferrin (the major iron-carrying protein in plasma) may release iron ions to catalyse the oxidation of LDL. Transferrin that had been incubated at pH 5.5 released approximately 10% of its bound iron in 24 h, as measured by ultrafiltration and atomic absorption spectroscopy. Furthermore, transferrin co-incubated with LDL and L-cysteine at pH 5.5 resulted in the oxidation of the LDL as measured by thiobarbituric acid-reactive substances and electrophoretic mobility. This effect was observed at transferrin concentrations as low as 40% of its average plasma concentration. The release of iron from transferrin in atherosclerotic lesions due to a localised acidic pH may help to explain why LDL oxidation occurs in these lesions.
authors.affiliation: Department of Biochemistry and Physiology, School of Animal and Microbial Sciences, University of Reading, Berks, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Lamb
authors.forename: D S
authors.initials: DS
authors.lastname: Leake
mesh_terms: D006801:Humans; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D010084:Oxidation-Reduction; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014168:Transferrin / Q000378:metabolism*
chemical_list: D008077:Lipoproteins, LDL; D017392:Thiobarbituric Acid Reactive Substances; D014168:Transferrin; D007501:Iron