表面活性剂对细胞色素C的作用及光诱导还原的影响

Effects of different classes of surfactants on cytochrome c and its photoreduction process

通过UV-Vis吸收光谱、普通荧光和同步荧光光谱、圆二色(CD)光谱等技术研究了表面活性剂(阴离子表面活性剂-琥珀酸二辛酯磺酸钠AOT、阳离子表面活性剂-十六烷基三甲基溴化铵、两性离子表面活性剂-3[(3-胆固醇氨丙基)二甲基氨基]-1-丙磺酸CHAPS)对细胞色素C(Cytochrome c,Cyt c)的相互作用及光诱导Cyt c还原的影响。结果显示:表面活性剂能够与Cyt c相互作用,进而影响Cyt c蛋白的结构及功能的表达。阴离子型表面活性剂AOT与Cyt c发生直接相互作用;阳离子型表面活性剂DTAB与Cyt c不发生作用或作用很小;两性离子型表面活性剂CHAPS是通过静电作用与Cyt c发生相互作用,作用强度很弱,远远低于AOT与Cyt c之间的相互作用。表面活性剂的加入改变Cyt c中Tyr和Trp残基微环境。AOT浓度达到1.25×10^(-3)mol·L^(-1)时Cyt c变性。并且研究结果表明,表面活性剂的存在抑制光诱导细胞色素C的还原,且抑制能力DTAB>CHAPS>AOT。

Applied with UV-Vis absorption,synchronous fluorescence and CD spectra,we studied the interactions between cytochrome c and different classes of surfactants,including anionic surfactant sodium bis（ 2-ethylhexyl） sulfosuccinate（ AOT）,cationic surfactant dodecyltrimethyl ammonium bromide（ DTAB） and zwitterionic surfactant 3-[（ 3-cholamidopropyl） dimethylammonio]propanesulfonate（ CHAPS）. Experimental results showed that the surfactants could interact with Cyt c and affect protein＇s functions.Anionic surfactant AOT can directly interact with Cyt c; while cationic surfactant DTAB can weakly react with Cyt c. Zwitterionic surfactant CHAPS can react with Cyt c by electrostatic,but the interaction was weak and far lower than the interaction between AOT and Cyt c.Adding surfactants can change the microenvironment of Tyr and Trp residues of the Mb.In AOT solution with concentration of 1. 25×10^-3mol·L^-1,Cyt c can be denatured.And the result showed that the presence of surfactants can restrain the photoreduction of Cyt c,and the inhibition of surfactants were DTABCHAPSAOT.