Proton flux induced by free fatty acids across phospholipid bilayers: New evidences based on short-circuit measurements in planar lipid membranes

被引：7

作者：

Arcisio-Miranda, Manoel ^{[1
]}

Abdulkader, Fernando ^{[1
]}

Brunaldi, Kellen ^{[1
]}

Curi, Rui ^{[1
]}

Procopio, Joaquim ^{[1
]}

机构：

[1] Univ Sao Paulo, Dept Fisiol & Biofis, Inst Ciencias Biomed, BR-05508900 Sao Paulo, Brazil

来源：

ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS | 2009年 / 484卷 / 01期

基金：

巴西圣保罗研究基金会;

关键词：

Fatty acids; Proton transport; Cholesterol; Cardiolipin; Membrane structure; FLIP-FLOP; INTRACELLULAR PH; PLASMA-MEMBRANE; TRANSPORT; CARDIOLIPIN; MECHANISMS; CHOLESTEROL; DIFFUSION; MODEL; PERMEABILITY;

D O I：

10.1016/j.abb.2009.01.019

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：

Free fatty acids (FFA) are important mediators of proton transport across membranes. However, information concerning the influence of the Structural features of both FFA and the membrane environment on the proton translocation mechanisms across phospholipid membranes is relatively scant. The effects of FFA chain length, unsaturation and membrane composition on proton transport have been addressed in this study by means of electrical measurements in planar lipid bilayers. Proton conductance (G(H)(+)) was calculated from open-circuit voltage and short-circuit current density measurements. We found that cis-unsaturated FFA caused a more pronounced effect on proton transport as compared to Saturated and trans-unsaturated FFA. Cholesterol and cardiolipin decreased membrane leak conductance. Cardiolipin also decreased proton conductance. These effects indicate a dual modulation of protein-independent proton transport by FFA: through a flip-flop mechanism and by modifying a proton diffusional pathway. Moreover the membrane phospholipid composition was shown to importantly affect both processes. (C) 2009 Elsevier Inc. All rights reserved.

引用

页码：63 / 69

页数：7