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Spontaneous oscillation of membrane potential in surface modified polyamino acid membrance

表面改性聚氨基酸膜膜电位的自发振荡

基本信息

批准号：
07651115
负责人：
HIGUCHI Akon
金额：
$ 0.38万
依托单位：
SEIKEI UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

Chemically modified poly (gamma-methyl-L-glutamate) membranes having several lengths of diamine scgments were prepared. The membrane potential, DELTAphi, was measured in cells that consisted of two chambers separated by the membranes. The potential was measured using a digital multimeter with Ag/AgCl electrodes, and the data were transferred to a 32-bit personal computer.The modified membranes generated oscillation of membrane potential under a conceutration gradient of several salts, although nonmodified membranes showed constant potential. The oscillation of membrane potential is considered to be caused by the fluctuation of the fixed charge density originating from the themal fluctuation of partially ionized amine segments in the modified membranes. The amplitude of the oscillation was greater in the modified membranes having longer diamine segments.It was also influenced by the salts used, and the highest amplitude of the oscillation was observed when LiCl was used as the salt. The amplitudes of the oscillation of membrane potential measured using several salts were observed to increase in the following order at C_O=0.1M,C_1=1mM,_pH=10 and 25^OC : CsCl=KCl<<Na_2CO_3<NaNO_3=Na_2SO_4<<LiCl. Not only the anion but also the cation in the salts was found to affect the amplitude of the oscillation of membrane potential. The amplitudes of oscillation in the membrane potential were observed to be higher when the ionic radius of the cation in the salts was less and the hydration radious of the cation in the salts was higher in this study (i.e., CsCl=KCl<NaCl<LiCl).Fast Fourier transport analysis revealed that the oscillation of membrane potential is not chaotic but has specific frequencies. It might be possible to recognize a particular salt present in the solution from the information on the amplitude and the power spectrum of fast Fourier transport in the oscillation of membrane potential.

制备了具有不同长度二胺片段的化学改性聚(γ-甲基-L-谷氨酸)膜。膜电位DELTAphi是在由膜隔开的两个腔室组成的细胞中测量的。用带有Ag/AgCl电极的数字万用表测量了膜的电位，并将数据传输到32位个人计算机上。尽管未改性膜的电位是恒定的，但在几种盐的浓度梯度下，改性膜的膜电位会发生振荡。膜电位的振荡被认为是由改性膜中部分电离的胺链段的热波动引起的固定电荷密度的波动引起的。二胺链段较长的改性膜的振荡幅度较大，且受所用盐的影响，以氯化锂为盐时，振荡幅度最大。在C_O=0.1M、C_1=1 mm、_pH=10和25℃：CsCl=KCl&lt；&lt；Na_2CO_3&lt；NaNO_3=Na_2SO_4&lt；&lt；LiCl.时，用几种盐测得的膜电位振荡幅度依次增大发现盐中的阴离子和阳离子不仅影响膜电位的振荡幅度，而且影响膜电位的振荡幅度。在本研究中，当盐中阳离子的离子半径较小、阳离子在盐中的水化半径较大时，膜电位的振荡幅度较大。快速傅立叶输运分析表明，膜电位的振荡不是混沌的，而是具有特定的频率。根据膜电位振荡中快速傅立叶传递的幅度和功率谱的信息，有可能识别出溶液中存在的特定盐。