Gramicidin derivatives as membrane-based pH sensors

被引：24

作者：

Borisenko, V ^{[1
]}

Zhang, ZH ^{[1
]}

Woolley, GA ^{[1
]}

机构：

[1] Univ Toronto, Dept Chem, Toronto, ON M5S 3H6, Canada

来源：

BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES | 2002年 / 1558卷 / 01期

基金：

加拿大自然科学与工程研究理事会;

关键词：

peptide; engineering; single molecule; pH gradient; proton; isomerization;

D O I：

10.1016/S0005-2736(01)00415-1

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Ion channels provide a means for sensitive pH measurement at membrane interfaces. Detailed knowledge of the structure and function of gramicidin channels permits the engineering of pH-sensitive derivatives. Two derivatives, gramicidin-ethylenediamine and gramicidin-histamine, are shown to exhibit pH-dependent single-channel behaviour over the pH ranges 9-11 and 6.5-8.5, respectively. Thermal isomerization of a carbamate group at the entrance of the channels leads to a pattern of steps in single-channel recordings. The size of the steps depends on the time-averaged degree of protonation of the appended group (ethylenediamine or histamine). Measurement of the size of the steps thus permits single-molecule pH sensing under symmetrical pH conditions or in the presence of a pH gradient. (C) 2002 Elsevier Science B.V. All rights reserved.

引用

页码：26 / 33

页数：8

共 48 条

[1] RAPID LONG-RANGE PROTON DIFFUSION ALONG THE SURFACE OF THE PURPLE MEMBRANE AND DELAYED PROTON-TRANSFER INTO THE BULK [J].