title: Reduction potential of iron in transferrin.
abstract: The reduction potential of Fe3+ in transferrin was measured spectrophotometrically by equilibration with methyl viologen in the presence of sodium dithionite. For an ionic strength near 0.1 M at 25 degrees C and pH 7.3 under 0.048 atm. CO2, half of the iron is reduced at a potential near -0.40 V (vs. standard hydrogen electrode). At least one disulfide bond of the protein is partially reduced at a potential of -0.44 V, as evidenced by reaction with [14C]iodoacetate.
mesh_terms: D004220:Disulfides; D004227:Dithionite; D005290:Ferric Compounds; D007461:Iodoacetates; D019807:Iodoacetic Acid; D007501:Iron; D010084:Oxidation-Reduction; D010269:Paraquat; D012996:Solutions; D013053:Spectrophotometry; D014168:Transferrin
chemical_list: D004220:Disulfides; D005290:Ferric Compounds; D007461:Iodoacetates; D012996:Solutions; D014168:Transferrin; D004227:Dithionite; D007501:Iron; D010269:Paraquat; D019807:Iodoacetic Acid