摘要
为了探究肌红蛋白表面60位的Asp突变为Lys后对蛋白荧光强度的影响,在模拟生理条件下,利用荧光法和圆二色法对WT Mb及D60K Mb的结构及荧光光谱特性进行了对照研究,结果表明D60K Mb的荧光量子产率远大于WT Mb。通过研究pH值和结构对荧光量子产率的影响,发现Mb 60位天冬氨酸(Asp)突变为赖氨酸(Lys)后,蛋白表面电荷发生改变,导致蛋白的荧光量子产率明显增强;同时使蛋白内部的芳香族氨基酸较原来更暴露,极性增强,激发态分子的去激发过程由原来的无辐射能量转移为主转变为辐射能量转移为主,最终导致荧光强度增强。
To study the role of surface-charged Asp60in the fluorescence intensity,under simulative physiological conditions of animal body,the difference in structure and fluorescence spectral characteristics between M b(W T)and Mb(D60K)was studied by fluorescence spectroscopy and circular dichroism.The results indicated that the fluorescence quantum yield of(D60K)was far more than that of Mb,which may correlate with pH and the structure of Mb.With a further research,this phenomenon was caused by the change of external charge when amino acid Asp60of myoglobin was replaced by Lys,which enhanced the polarity and exposure extent of aromatic amino acids of myoglobin,and the decay process of myoglobin molecules which were excited from non-radiative decay to radiative decay.
作者
唐乾
李如玉
职秋雁
曹洪玉
王立皓
郑学仿
LI Ruyu;ZHI Qiuyan;ZHENG Xuefang;TANG Qian;CAO Hongyu;WANG Lihao(College of Life Science and Biotechnology , Dalian University , Dalian 116622, Liaoning, P. R. China;Liaoning Key Laboratory of Bio-organic Chemistry , Dalian University , Dalian 116622, Liaoning, P. R. China;School of Environmental and Chemical Engineering, Dalian University, Dalian 116622, Liaoning, P. R. China)
出处
《影像科学与光化学》
CAS
CSCD
北大核心
2017年第6期788-796,共9页
Imaging Science and Photochemistry
基金
国家自然科学基金项目(21571025
21271036
21601024)资助
关键词
肌红蛋白
D60KMb
光谱
结构
荧光量子产率
myoglobin
mutant(D60k)
spectroscopy
structure
fluorescence quantum yield
