pH modulation of transport properties of alamethicin oligomers inserted in zwitterionic-based artificial lipid membranes
pH modulation of transport properties of alamethicin oligomers inserted in zwitterionic-based artificial lipid membranes
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DOI：
10.1016/j.bpc.2007.08.009
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发表时间：
2007-11-01
影响因子：
3.8
通讯作者：
Luchian, Tudor
中科院分区：
文献类型：
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作者：
Chiriac, Roxana;Luchian, Tudor
生物膜的电特性是膜穿透肽的功能和生理表现的主要决定因素，并且这些特性易于受到周围水介质的性质的调节。在这项工作中，我们证明了pH值在调节基于两性离子的人工脂质膜的电特性中起着至关重要的作用。通过评价包埋的丙甲霉素低聚物在宽范围的pH值（即，0.65、2.08、2.94、7和10.1）。我们的数据强烈支持的范例的pH值依赖性的变化的表面和膜偶极电位，连同可能的侧向压力的影响内的脂质膜，导致一个非单调调制的电导率的丙甲霉素低聚物。正如预期的那样，与较大的低聚物相比，通过丙甲霉素低聚物的输送性质的pH调节对于具有稍微更好的阳离子选择性的较窄的孔（即，第一导电状态）更明显。(C)2007 Elsevier B.V.保留所有权利。
Electric features of biological membranes are major determinants of the function and physiological manifestation of membrane-penetrating peptides, and such features are prone to be modulated by the properties of the surrounding aqueous medium. In this work, we demonstrate that pH plays crucial roles in modulating electric characteristics of zwitterionic-based artificial lipid membranes. The effect of pH on electrical properties of such membranes was probed by evaluating the transport properties of embedded alamethicin oligomers over a wide range of pH values (i.e., 0.65, 2.08, 2.94, 7 and 10.1). Our data strongly support the paradigm of a pH-dependent variation of the surface and membrane dipole potential which, in conjunction with possible lateral pressure effects within the lipid membrane, lead to a non-monotonic modulation of the electrical conductance of alamethicin oligomers. As expected, pH modulation of transport properties through the alamethicin oligomer is more visible for narrower pores (that is, the 1st conductive state) with slightly better cation selectivity as compared to larger oligomers. (C) 2007 Elsevier B.V. All rights reserved.