肌红蛋白(Myoglobin,Mb)是哺乳动物细胞主要是肌细胞贮存和分配氧的蛋白质, 由一条多肽链和一个血红素辅基构成,其血红素铁在氧气的传递和运输中起到关键作用。文章利用紫外-可见光谱法对肌红蛋白的血红素铁和外加金属离子M(Ⅱ)[Cu(Ⅱ), Zn(Ⅱ)和Co(Ⅱ)] 的直接相互作用进行了研究。结果发现, 金属离子M(Ⅱ)与肌红蛋白活性中心的Fe(Ⅱ)发生了直接相互作用,外加金属离子将铁离子从肌红蛋白中“拖拽”出来,形成部分空位肌红蛋白衍生物。同时研究了外界条件,如离子浓度对这种相互作用的影响,发现随着外加金属离子量的增加这种相互作用逐渐增强,其作用强度依次为Co(Ⅱ)>Zn(Ⅱ)>Cu(Ⅱ)。 研究证实了肌红蛋白的血红素铁与金属离子之间存在直接相互作用,并且离子浓度对这种相互作用有影响。
Myoglobin (Mb) made up of a multipeptides train and a heme prosthetic group is a kind of protein taking charge of O2 stock and distribution in mammal cells, especially in muscle cells. The heme-iron plays a key role in O2 transfer and transport. In the present paper, the direct interaction between heine-iron of myoglobin and additional metal ions [Cu( Ⅱ ), Zn( Ⅱ) and Co(Ⅱ)] was studied by UV-Vis spectra. It was found that heine-iron of myoglobin directly interacted with additional Cu( Ⅱ ), Zn( Ⅱ) and Co(Ⅱ), these metal ions could drag iron ion out from heme prosthetic group of myoglobin, and subsequently myoglobin became myoglobin derivatives lacking iron ion. At the same time, the effect of the additional metal ions concentration on the direction interaction was studied. It was shown that the direct interaction increased gradually with the amount of external metal ions added. When the ratio of Mb and metal ions is 1 : 10, the interaction intension between the three metal ions and Mb is Co( Ⅱ ), Zn( Ⅱ ) and Cu( Ⅱ ) in turn. For the first time, the authors confirmed that the direct interaction has occurred between heme-iron of myoglobin and additional metal ions, and saw about how the metal ions intension affects the direct interaction.