On the mechanism of ion transport through lipid membranes mediated by PEGylated cyclic oligosaccharides (CyPLOS): An ESR study
On the mechanism of ion transport through lipid membranes mediated by PEGylated cyclic oligosaccharides (CyPLOS): An ESR study
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DOI：
10.1016/j.bbamem.2013.05.017
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发表时间：
2013-09-01
影响因子：
3.4
通讯作者：
D'Errico, Gerardino
中科院分区：
文献类型：
--
作者：
Busi, Elena;Vitiello, Giuseppe;D'Errico, Gerardino
用电子自旋共振（ESR）方法研究了CyPLOS（环状磷酸连接寡糖，2）的离子转运活性。CyPLOS是一种由四甘醇（TEG）链修饰的糖基合成离子转运体。离子载体与脂质双层的相互作用模式已经通过定量分析特别合成的自旋标记的CyPLOS类似物（6）的ESR光谱中的扰动，以及平行地，在与2混合的自旋标记的脂质的光谱中的扰动来研究。结果表明，环状糖骨架的定位靠近脂质头基，主要暴露于水性介质。携带末端苄基的TEG链深深插入脂质酰基链之间，显示出良好的流动性和柔性。因此，酰基链堆积的顺序显著降低，并且双层中的水渗透增强。由此产生的不对称扰动的双层导致其局部不稳定，从而促进，通过非特异性机制，离子运输通过膜。(C)2013爱思唯尔有限公司版权所有。
The mechanism underlying the ionophoric activity of CyPLOS (cyclic phosphate-linked oligosaccharide, 2), a carbohydrate-based synthetic ion transporter decorated with four tetraethylene glycol (TEG) chains, has been investigated by an integrated electron spin resonance (ESR) approach. The mode of interaction of the ionophore with lipid bilayers has been studied by quantitatively analyzing the perturbations in the ESR spectrum of an ad hoc synthesized spin-labeled CyPLOS analog (6), and, in parallel, in the spectra of spin-labeled lipids mixed with 2. The results point to a positioning of the cyclic saccharide backbone close to the lipid headgroups, largely exposed to the aqueous medium. The TEG chains, carrying a terminal benzyl group, are deeply inserted among the lipid acyl chains, showing good mobility and flexibility. As a consequence, the order of the acyl chain packing is significantly reduced, and water penetration in the bilayer is enhanced. The resulting asymmetric perturbation of the bilayer leads to its local destabilization, thus facilitating, through a non-specific mechanism, the ion transport through the membrane. (C) 2013 Elsevier B.V. All rights reserved.