【作者】 李乐军；

【导师】 陈树德；

【作者基本信息】 华东师范大学 ， 生物物理学， 2005， 硕士

【摘要】 本实验室前期的实验研究发现,胞间信号分子胰岛素是脉冲电场引发细胞生物学效应的一个作用位点。为了阐明脉冲电场通过胞间信号分子对细胞产生的生物学效应,本文采用了普通荧光光谱、同步荧光光谱和激光拉曼光谱三种光谱方法,对脉冲电场对三种蛋白质分子(胰岛素、牛血清白蛋白和溶菌酶)的构象影响以及脉冲电场的时间效应进行了研究。普通荧光光谱发现,随着电场作用时间的增加,三种蛋白质的普通荧光光谱均有不同程度的变化。进一步利用同步荧光光谱研究,发现脉冲电场改变了蛋白质活性部位的色氨酸和酪氨酸两种芳香族氨基酸的荧光强度,表明脉冲电场改变了氨基酸所处的微环境,进而表明蛋白质的结构发生了改变。利用激光拉曼光谱,详细研究脉冲电场作用后蛋白质的各种功能键和二级结构的变化,发现脉冲电场改变了蛋白质的二硫键的振动模式,影响了酪氨酸、色氨酸和苯丙氨酸残基所处的微环境,改变了蛋白质的二级结构,使蛋白质更趋向于无规结构。这些实验研究,从分子水平为脉冲电场的生物学效应分子机理的研究提供了有力的依据。更多还原

【Abstract】 It was shown by our previous experiments in our laboratory that insulin, one of the intercellular molecules, was a reactive site of the bio-effects induced by Pulsed Electric Field (PEF).In order to elucidate the indirect bio-effects of PEF exerted on cells through some intercellular signal molecules, three spectroscopic methods, Fluorescence Spectroscopy, Synchronous Fluorescence Spectroscopy and Laser Raman Spectroscopy, were utilized to investigate the conformational changes of three kinds of proteins (insulin, bovine serum albumin and lysozyme) and the time-dependent effects induced by PEF.It was demonstrated by the Fluorescence Spectroscopy that the fluorescence spectra of the proteins were altered by PEF. The micro-environments of two aromatic amino acids, tyrosine and tryptophan, located in the active region of the proteins, were altered by PEF indicated by the Synchronous Fluorescence Spectroscopy. These results indicated that the structures of the proteins were changed by PEF treatment.In order to investigate whether the structures of the proteins would be affected by PEF, Laser Raman Spectroscopy was selected. Some important functional bonds and the secondary structure of proteins were studied in detail by Laser Raman Spectroscopy. The results showed that PEF has changed the vibration modes of the S-S bond, has affected the micro-environments of tyrosine, tryptophan, and phenylalanine and has changed the secondary structure, which tended to be irregular.The experimental research work in this paper would provide some useful information on the molecular level for the study on mechanism of the PEF-induced bio-effects.更多还原