钠氢交换体胞质结构域中富含组氨酸的氨基酸簇的特征分析

Characterization of a histidine rich cluster of amino acids in the cytoplasmic domain of the Na+/H+ exchanger.

作者信息

Dibrov P, Murtazina R, Kinsella J, Fliegel L

机构信息

Department of Biochemistry, Faculty of Medicine, University of Alberta, Edmonton, Canada.

出版信息

Biosci Rep. 2000 Jun;20(3):185-97. doi: 10.1023/a:1005567519792.

DOI:10.1023/a:1005567519792

PMID:11095118

Abstract

We examined the function of a highly conserved Histidine rich sequence of amino acids found in the carboxyl-terminal of the Na+/H+ exchanger (NHE1). A fusion protein containing the sequence HYGHHH (540545) and the balance of the carboxyl terminal of the protein did not bind calcium but bound to an immobilized metal affinity column and could be used to partially purify the exchanger protein. Mutation of the sequence to either HYGAAA or HYGRRR did not affect activity of the intact protein. Mutation to HHHHHH did not affect proton activation of the Na+/H+ exchanger or localization but caused a decreased maximal velocity suggesting that this conserved sequence is important in maximal activity of the Na+/H+ exchanger.

摘要

我们研究了在钠氢交换体（NHE1）羧基末端发现的一段高度保守的富含组氨酸的氨基酸序列的功能。一种包含序列HYGHHH（540545）以及该蛋白质羧基末端其余部分的融合蛋白不结合钙，但能结合到固定化金属亲和柱上，可用于部分纯化交换体蛋白。将该序列突变为HYGAAA或HYGRRR不影响完整蛋白质的活性。突变为HHHHHH不影响钠氢交换体的质子激活或定位，但导致最大速度降低，这表明该保守序列对钠氢交换体的最大活性很重要。