辐射引发核组蛋白与咖啡酸之间电荷转移保护效应的 ESR 研究  

ESR STUDY ON RADIATION INDUCED ELECTRON TRANSFER BETWEEN NUCLEOHISTONE AND CAFFEIC ACID

作　　者：朱幼南[1,2] 屠铁城[1,2] 董继荣 张加山 林念芸[1,2] 

机构地区：[1]中国科学院辐射化学开放研究实验室 [2]上海原子核研究所

出　　处：《辐射研究与辐射工艺学报》1997年第4期201-204,共4页Journal of Radiation Research and Radiation Processing

基　　金：国家自然科学基金

摘　　要：核组蛋白咖啡酸二元混合体系在ｐＨ９、７７Ｋ辐照并测定的ＥＳＲ谱主要呈现为咖啡酸阴离子自由基的信号；用计算机模拟ＥＳＲ波谱方法，对二元体系以其组分核组蛋白和咖啡酸单谱信号线性叠加拟合进行重组，经处理后得到该体系中咖啡酸自旋转移的百分率。结果显示，随着体系中核组蛋白含量的增加，自旋转移百分率也随之增加，表明体系内发生了电子自旋由核组蛋白向咖啡酸的转移。Radiation induced electron transfer between nucleohistone and caffeic acid and the radiation protection effect by caffeic acid have been studied A series of binary molecular aggregates of nucleohistone and caffeic acid with weight ratios varied from 1∶1 to 60∶1 at pH9 were irradiated and observed at 77K using ESR spectrometer The ESR spectra recorded at 77K indicate that ΔHpp (083～095 mT) of central peak from mixed aggregates with several moleoular ratios are close to ΔHpp (094mT) of caffeic acid alone and quite different from ΔHpp (25mT) of nucleohistone It is suggested that caffeic acid anion radic al is the main radical product PST(%) defined as the percentage of the spin concentration of caffeic acid arising from transfer of captured electron by nucleohistone in the total spin concentration of caffeic acid could be obtained by resolution of composite ESR spectra It is obvious that PST increased with the increase of nucleohistone content and reaches more than 90% from weight ratios 10∶1 to 60∶1 The results indicates that electron transfer from nucleohistone to caffeic acid occurred within the mixed aggregtes

关 键 词：核组蛋白 咖啡酸 电子转移 ESR波谱 辐射损伤 

分 类 号：Q691.2[生物学—生物物理学] R818.03[医药卫生—放射医学]