细胞色素C和含心磷脂的人工脂膜相互作用

Lnteraction Between Cytochrome C and Cardiolipin-Containing Liposome Membrane

本文报告以芘为荧光探剂,研究细胞色素C和含心磷脂的人工脂膜的相互作用。1.由于芘和细胞色素C的血红素团之间的能量转移,细胞色素C与心磷脂结合引起芘的单体荧光发射峰(395nm)强度下降。这种淬灭效应受脂膜的相行为影响,在液晶相时淬灭效应小于凝胶相;2.氧化态细胞色素C与还原态相比,对心磷脂结合的视和度稍高;3.在以芘的激发二聚体荧光峰(475nm)强度与单体荧光峰强度之比做为脂膜流动性的指标,发现还原态细胞色素C与含心磷脂脂膜结合后引起流动性增加的效应高于氧化态的结合。

Fluorescent probe pyrene was used to investigate the interaction of cytochrome c with liposome membrane cantaining cardiolipin and dipalmitoylphosphatidylcho line.The binding of cytochrome c to cardiolipin was monitored by measuring the decrease in the fluorescence intensity of pyrene monomer at 395nm due to energy transfer from pyrene to heme.The decrease in fluorescence of pyrene was affected by phase phenomen an of membrane studied.In liquid-crystalline bilayer mesured at 46℃ (above DPPC phase transition temperature), the quenching effect by cytochrome c was less than that in gel state. Double reciprocal plot of the percentage quenching of pyrene fluorescence intensity vs the concentration of cytochrome c showed that the affinity of the oxidized cytochrome c to the membrane was somewhat higher than that for reduced form.Either reduced or oxidized form of cytochrome c could fluidize the membrane studied, but the fluidizing effect of reduced form was more observable.