title: On the origin of the non-haemic iron transferrin ESR signal: ESR investigations on histidine-iron-ascorbic acid systems.
abstract: The nature of the ferric high spin iron complex located at g = 4.3 has been investigated by means of electron spin resonance spectroscopy. It could be shown that the iron is bound to two histidines, three ascorbic acids, and one bicarbonate. This agrees well with previous findings according to which the ligand field of iron is composed mainly of oxygen and nitrogen atoms. Another low-field signal located at g = 9.5 appears always concomitantly with the g = 4.3 signal. It should be due, therefore, to a transition between the two sublevels of the low-lying Kramers doublet in one principal direction.
mesh_terms: D001205:Ascorbic Acid; D004578:Electron Spin Resonance Spectroscopy; D006639:Histidine; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis*; D014168:Transferrin
chemical_list: D014168:Transferrin; D006639:Histidine; D007501:Iron; D001205:Ascorbic Acid