title: Properties of the cupric sites in bovine superoxide dismutase studied by nuclear-magnetic-relaxation measurements.
abstract: Proton nuclear-relaxation rates have been measured as a function of frequency, temperature, pH and cyanide concentration in aqueous solutions of superoxide dismutase from bovine erythrocytes. The results show that, whereas for pH less than or equal to 9 only one water molecule is bound to each Cu2+ ion, at higher pH a second co-ordination site for OH- becomes available; it is proposed that this involves cleavage of the bond between Cu2+ and the histidine residue that bridges to Zn2+.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D003300:Copper; D003486:Cyanides; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D013057:Spectrum Analysis; D013482:Superoxide Dismutase; D013696:Temperature
chemical_list: D003486:Cyanides; D003300:Copper; D013482:Superoxide Dismutase