竹红菌乙素作猝灭剂研究F_o构象方法的建立  

A Method of Studying Conformation of MembraneBound Fo Using Tryptophan Fluorescence Quenching by Hypocrellin B

作　　者：李生广[1] 封朝阳[1] 乐加昌[1] 徐霆[1] 林治焕[1] 

机构地区：[1]中国科学院生物物理研究所

出　　处：《生物化学与生物物理进展》1998年第1期49-53,共5页Progress In Biochemistry and Biophysics

基　　金：国家自然科学基金;北京大学蛋白质工程及植物基因工程国家重点实验室基金;生物物理研究所基金

摘　　要：线粒体Ｆ１Ｆｏ复合体Ｆｏ部分ａ亚基的色氨酸荧光可被竹红菌乙素（ｈｙｐｏｃｒｅｌｉｎＢ，ＨＢ）猝灭．不同温度下测定ＳｔｅｒｎＶｏｌｍｅｒ图的结果显示，猝灭常数（Ｋｓｖ）随温度的增加而加大，时间衰变荧光的结果显示，荧光寿命随ＨＢ浓度的增加而减小，加入不同浓度的ＨＢ，Ｆ１Ｆｏ复合体的吸收峰没有位移．这些实验结果支持动态猝灭机理．ＨＢ还具有有效猝灭浓度低，不影响酶的活力；在脂相和水相的分布比率可高达１６５６０∶１；实验操作简便等优点．因此ＨＢ可作为理想的疏水相荧光猝灭剂，研究与膜结合的Ｆ１Ｆｏ复合体中镶嵌于膜脂内Ｆｏ的构象变化．The tryptophan fluorescence of a subunit of Fo moiety of mitochondrial F1Fo can be quenched by the addition of Hypocrellin B. The determination of the SternVolmer plot at different temperatures is carried out. The result shows that the Ksv increased with the increase of temperature. The experimental result of the timeresolved fluorescence decay shows the decrease of lifetime of tryptophan fluorescence of Fo with the increase of concentration of HB. No shift in the absorbance spectra of F1Fo were occurrent at varying concentration of HB. The results support the dynamic quenching. In addition, HB possess the necessary characters to be used as a quencher in the hydrophobic phase as follows: the low concentration of effective quenching; no effect on the activity of F1Fo; the ratio of the partition coefficients between lipidphase and waterphase as high as 16 560∶1. So HB can be used as a ideal fluorescence quencher for the study of conformational change of Fo moiety of membranebound F1Fo complex.

关 键 词：竹红菌乙素 荧光猝灭 构象 

分 类 号：Q731[生物学—分子生物学]