Hemin和CopC相互作用的光谱和分子模拟研究

本文通过光谱技术以及分子模拟手段研究了CopC与hemin的相互作用。紫外可见光谱表明hemin中Fe³⁺可能与CopC中的组氨酸(His1或His91)形成配位。此外,荧光光谱表明CopC与hemin的主要弱作用力为疏水作用力。圆二色谱、化学变性、荧光寿命以及同步荧光实验表明hemin与CopC的配位使得CopC的稳定性降低,并且色氨酸周围环境的疏水性减弱。紫外可见及荧光光谱表明,两者结合常数在10⁶左右,结合比为1,hemin与CopC中唯一的色氨酸(Trp83)的距离为1.06 nm。最后通过分子对接模拟了CopC与hemin的相互作用,结果表明hemin中Fe³⁺可能与CopC中的组氨酸(His1)形成与卟啉环平面垂直的轴向配位,并且与Trp83距离为0.96 nm,与实验结果一致。

Study on the interaction between Hemin and CopC by spectroscopy and docking methods

In this paper,the interaction between CopC and hemin was studied by means of spectroscopy and molecular simulation.The UV-vis spectra indicate that Fe³⁺in hemin might form axial coordination with histidine(his1 or his91)in CopC,which was perpendicular to the plane of porphyrin ring.In addition,the fluorescence spectra showed that the main weak interaction between CopC and hemin was hydrophobic.Circular dichroism,chemical denaturation,fluorescence lifetime and synchronous fluorescence experiments showed that the coordination of hemin and CopC changed the structure of CopC,and then changed the environment around tryptophan.The binding constant was about 10⁶,the binding ratio was 1,and the distance between hemin and tryptophan in CopC was 1.06 nm.Finally,the interaction between CopC and hemin was simulated by molecular docking,and the results were consistent with the experimental results.