【摘要】 电喷雾质谱正离子模式研究了在酸和盐的诱导下蛋白质的折叠状态.研究表明,用酸去折叠后的溶菌酶在相同电喷雾质谱条件中有表现出比紧密折叠的蛋白质相对低的电荷状态,而细胞色素C的电荷状态却相反.在相当宽的挥发性盐浓度范围内,电喷雾质谱对蛋白质的检测都表现出良好的信号,而在高盐浓度下,传统的检测方法如圆二色谱则无法检测,这一结果为高盐浓度的下蛋白质的研究提供一个手段.同时考察了主要仪器条件的设定对测定的影响.更多还原

【Abstract】 The application of positive ion mode mass spectrometry(MS) to large biomolecules has been revolutionized in the past decade with the development of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization(MALDI) techniques. ESI permits solvent evaporation and sublimation of large biomolecules into the gaseous phase, respectively. ESI has allowed the determination of accurate molecular mass and the detection of chemical modification at high sensitivity. The interface of mass spectrometry hardware and new extended mass spectrometric methods has resulted in the use of MS for protein conformations (native, denatured, folding intermediates), protein folding/unfolding and protein-protein or protein-ligand interactions. In this paper, ESI-MS was used to study protein charge statement with acid and salt. HEWL (hen egg white lysozyme) and Cytochrome C were taken for example to investigate their foldings under different condition. It was found that the concentration of salt had not much influence on protein folding status and pH of the solution should be paid more attention to different protein during the experiment.This technique is appropriate for the protein observation in high salt solution. At the same time, instrument parameter was considered. In this paper, the influence of ΔCS(capillary-skimmer voltage) was studied. WhenΔCS increased, the charge state of protein decreased. To extend this methodology, more native substance could be used to recognize anions by ESI-MS. This technique is hoped to do more work in continuing work.更多还原