基于时间分辨方法的LicT蛋白荧光动力学特性

发布时间：2018-03-20 17:28

本文选题：时间相关单光子计数　切入点：色氨酸　出处：《物理化学学报》2017年05期 　论文类型：期刊论文

【摘要】：使用时间分辨荧光方法,结合紫外吸收光谱和稳态荧光光谱技术,测量了LicT蛋白中色氨酸残基的荧光动力学特性,进而对LicT蛋白质激活前后的局部微环境和结构变化进行了研究。LicT蛋白质的激活态使得有关糖类利用的基因转录过程继续进行,促进机体新陈代谢。通过色氨酸残基的荧光发射和寿命的差异判断出激活型蛋白AC 141和野生型蛋白Q 22不同的结构性质和微环境差异。在此基础上,通过衰减相关光谱(DAS)和时间分辨发射光谱(TRES)阐释了两种蛋白色氨酸残基和溶剂的相互作用,说明了激活型AC 141的比野生型Q 22的结构更加紧密。此外,TRES还说明了蛋白中的色氨酸残基存在连续光谱弛豫过程。各向异性结果则对残基和整个蛋白的构象运动进行了阐述,说明了色氨酸残基在蛋白质体系内有独立的局部运动,且在激活型蛋白中该运动更加强烈。
[Abstract]:The fluorescence kinetic characteristics of tryptophan residues in LicT protein were measured by time-resolved fluorescence method, UV absorption spectroscopy and steady-state fluorescence spectroscopy. Then the changes of local microenvironment and structure before and after activation of LicT protein were studied. The activated state of Lict protein made the gene transcription process of carbohydrate utilization continue. Promoting metabolism. Based on the difference of fluorescence emission and lifetime of tryptophan residues, the differences in structure, properties and microenvironment of activated protein AC141 and wild type protein Q22 were determined. The interaction between tryptophan residues and solvents was explained by decay correlation spectroscopy (das) and time-resolved emission spectroscopy (TRES). The results show that the structure of activated AC141 is more compact than that of wild type Q22. In addition, Tres also shows that the tryptophan residue in the protein has a continuous spectral relaxation process. The anisotropic results illustrate the conformational motion of the residue and the whole protein. The results showed that the tryptophan residues had independent local movement in the protein system, and the movement was stronger in the activated proteins.
【作者单位】：华东师范大学精密光谱科学与技术国家重点实验室;中国科学院上海光学精密机械研究所;
【分类号】：O629.73;O657.3

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