菌紫质的Ser和Lys残基修饰对BR结构和功能的影响  

THE EFFECT OF MODIFICATION OF SER AND LYS RESIDUES ON THE STRUCTURE AND FUNCTION OF BACTERIORHODOPSIN(BR)

作　　者：胡坤生[1] 王敖金[1] 孙永泰[1] 

机构地区：[1]中国科学院生物物理研究所

出　　处：《生物物理学报》1996年第2期331-334,共4页Acta Biophysica Sinica

基　　金：中国科学院重大项目

摘　　要：用化学修饰研究了菌紫质（ＢＲ）的结构和功能的变化。用氮氧自由基分别对赖氨酸和丝氨酸进行修饰，研究结果表明在圆二色谱上（ＣＤ谱），与天然紫膜样品比较，两种自由基分别修饰赖氨酸（Ｌｙｓ）和丝氨酸（Ｓｅｒ）残基２４小时后的ＣＤ谱中均只有负峰，分别在５９６ｎｍ和６０２ｎｍ，５３５ｎｍ的正峰已消失，７２小时后５３５ｎｍ的正峰部分地恢复，但１２０小时后均未见进一步恢复。与未修饰的紫膜相比，两种自由基修饰的紫膜在Ｒａｍａｎ光谱上观察到中间体Ｍ４１２的相对量要明显增加。本文对这二种化学修饰引起的ＢＲ结构和功能变化进行了初步讨论。Chemical modification was used tO study the structure and function of BR.Lysine and serine residues were modified with free radical modifier S and modifier F.Compared with CD spectrum of normal purple membrane, for the samples treated with free radical modifier S and F respectively,24 hours after modification, 535nm positive peak disappeared, and negative peaks at 596nm and 602nm remain. 72 hours after modification, 535nm positive peak reappeared,and no further change was observed later than 120 hours after modification. Compared with unmodified BR, for the samples of two modified BR, the quantity of M412 increaseed. The effect of two kinds of modifier on the change of structure and function of BR were discussed.

关 键 词：生物膜 紫膜 丝氨酸 赖氨酸 菌紫质 化学修饰 

分 类 号：Q734[生物学—分子生物学]