Formation of a leakage-type ion pathway in lipid bilayer membranes by divalent cationic cyanine dyes in cooperation with inorganic phosphate. Role of the cyanine dye in uncoupling of oxidative phosphorylation.
Formation of a leakage-type ion pathway in lipid bilayer membranes by divalent cationic cyanine dyes in cooperation with inorganic phosphate. Role of the cyanine dye in uncoupling of oxidative phosphorylation.
复制标题
二价阳离子花青染料与无机磷酸盐配合在脂质双层膜中形成泄漏型离子途径。
DOI：
10.1016/s0021-9258(17)39345-6
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发表时间：
1985
影响因子：
4.8
通讯作者：
H. Terada
中科院分区：
文献类型：
--
作者：
N. Takeguchi;T. Saitoh;M. Morii;K. Yoshikawa;H. Terada
二价阳离子花菁染料如2，2 ′-[3-[2-（3-丁基-4-甲基-2-噻唑啉-2-亚基）-亚乙基]亚丙烯基]双[3-丁基-4-甲基噻唑啉碘化物]和铂酮在含无机磷酸盐（Pi）的介质中，当跨磷脂酰丝氨酸双层膜施加电位差时，引起大的膜电流波动。在没有Pi的情况下，染料在小于30 μ M的浓度下不诱导电流波动。电流波动的噪声分析表明，离子泄漏的路径的形成。从测量的油相和水相之间的界面张力，和水的渗透性穿过脂质体膜，Pi的结论是放松磷脂双层结构，导致在很大程度上减少的花青染料的浓度所需的诱导的泄漏型途径。在Pi的存在下，阳离子，如四丁基铵和四苯基鏻没有引起泄漏型途径，虽然他们在高浓度下有电泳效应。这些事实表明，双阳离子菁染料在线粒体中的氧化磷酸化解偶联的机制是不同的阳离子解偶联剂，如四丁基铵离子。
Divalent cationic cyanine dyes, such as 2,2'-[3-[2-(3-butyl-4-methyl-2-thiazoline-2-ylidene)-ethylidene] propenylene]bis[3-butyl-4-methylthiazolinium iodide] and platonin induced large membrane current fluctuation when an electrical potential difference was applied across a planar phosphatidylserine bilayer membrane in medium containing inorganic phosphate (Pi). Without Pi, the dyes did not induce current fluctuation at concentrations of less than 30 microM. Noise analysis of current fluctuation indicated formation of a pathway for ion leakage. From measurements of the interfacial tension between oil and aqueous phases, and of water permeability across liposomal membranes, Pi was concluded to relax the phospholipid bilayer structure, resulting in great reduction in the concentration of the cyanine dye necessary for induction of the leakage-type pathway. In the presence of Pi, cationic ions such as tetrabutyl ammonium and tetraphenyl phosphonium did not induce the leakage-type pathway, although they had electrophoretic effects at high concentrations. These facts suggest that the mechanism of the uncoupling of oxidative phosphorylation by dicationic cyanine dyes in mitochondria is different from that of cationic uncouplers such as tetrabutyl ammonium ion.