我们用~1HNMR双共振技术测定了在pH=7.04,温度303—319K范围内咪唑键合氧化型细胞色素c的平衡常数,从Van’t Hoff和Arrhenius方程得到键合的热力学常数△H°=48.5kJ·mol~(-1),△S°=184J·mol~(-1)·K~(-1)和活化能E_a=159kJ·mol~(-1),并与其它血红素蛋白和模型化合物的热力学常数作了比较和讨论.用饱和转移法归属了cyt c·Im的血红素环上甲基峰,首次用NMR方法确证咪唑在与氧化型cyt c反应中取代了轴向Met 80,形成新的Fe—N键. We measured the equilibrium constants of imidazole-bound oxidized cytochrome c at pH = 7.04 and at a temperature of 303-319K by ~ 1HNMR double resonance technique. The thermodynamic constants of bonding were obtained from the Van’t Hoff and Arrhenius equations. ΔH ° = 48.5kJ · mol -1, ΔS ° = 184J · mol -1 K -1 and activation energy Ea = 159kJ · mol -1, and were correlated with other heme proteins and The thermodynamic constants of the model compounds were compared and discussed. The saturation transfer method was assigned to the methyl peak on the heme ring of cyt c. Im. It was first confirmed by NMR that imidazole replaced axial Met 80 in reaction with oxidized cyt c , Forming a new Fe-N bond.