The antimicrobial peptide gramicidin S permeabilizes phospholipid bilayer membranes without forming discrete ion channels.
The antimicrobial peptide gramicidin S permeabilizes phospholipid bilayer membranes without forming discrete ion channels.
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DOI：
10.1016/j.bbamem.2008.08.017
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发表时间：
2008-12
影响因子：
3.4
通讯作者：
McElhaney, R. N.
中科院分区：
文献类型：
--
作者：
Ashrafuzzaman, Md.;Andersen, O. S.;McElhaney, R. N.
关键词：
我们检测了β-片环抗菌十肽gramicidin S （GS）对磷脂双层膜的渗透作用，这些双层膜是由两性离子二植酰基磷脂酰胆碱和阴离子二植酰基磷脂酰甘油的混合物形成的，或者是由具有不同碳氢化合物链长的单两性离子不饱和磷脂酰胆碱形成的，含有或不含胆固醇。在由磷脂酰胆碱形成的两性离子双分子层中，无论有无胆固醇，启动膜渗透所需的肽浓度和膜电位随双层厚度和胆固醇含量的变化不大。在所有测试的体系中，gs诱导的瞬态离子电导事件表现出广泛的电导范围，其受双层组成或厚度的影响很小。在两性离子磷脂酰胆碱双分子层中，GS的作用不依赖于跨膜电位的极性；然而，在磷脂酰胆碱和阴离子磷脂混合物形成的双层中，跨膜电位的极性变得重要，当含有gs的溶液相对于不含gs的溶液为正时，gs诱导的电导事件更加频繁。总的来说，这些结果表明，GS不会在磷脂双层中形成离散的，明确的，通道状结构，而是诱导各种各样的瞬态，不同大小的缺陷，这些缺陷有助于损害小电解质的双层屏障特性。
We examined the permeabilization of lipid bilayers by the β-sheet, cyclic antimicrobial decapeptide gramicidin S (GS) in phospholipid bilayers formed either by mixtures of zwitterionic diphytanoylphosphatidylcholine and anionic diphytanoylphosphatidylglycerol or by single zwitterionic unsaturated phosphatidylcholines having various hydrocarbon chain lengths, with and without cholesterol. In the zwitterionic bilayers formed by the phosphatidylcholines, without or with cholesterol, the peptide concentrations and membrane potentials required to initiate membrane permeabilization vary little as function of bilayer thickness and cholesterol content. In all the systems tested, the GS-induced transient ion conductance events exhibit a broad range of conductances, which are little affected by the bilayer composition or thickness. In the zwitterionic phosphatidylcholine bilayers, the effect of GS does not depend on the polarity of the transmembrane potential; however, in bilayers formed from mixtures of phosphatidylcholines and anionic phospholipids, the polarity of the transmembrane potential becomes important, with the GS-induced conductance events being much more frequent when the GS-containing solution is positive relative to the GS-free solution. Overall, these results suggest that GS does not form discrete, well-defined, channel-like structures in phospholipid bilayers, but rather induces a wide variety of transient, differently sized defects which serve to compromise the bilayer barrier properties for small electrolytes.
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影响因子：
4.8
作者：
Kondejewski, LH;Jelokhani-Niaraki, M;Hodges, RS
通讯作者：
Hodges, RS
DOI：
10.1034/j.1399-3011.2001.00893.x
发表时间：
2001-10-01
期刊：
JOURNAL OF PEPTIDE RESEARCH
影响因子：
--
作者：
Jelokhani-Niaraki, M;Prenner, EJ;Hodges, RS
通讯作者：
Hodges, RS
影响因子：
3.4
作者：
Jelokhani-Niaraki, Masoud;Hodges, Robert S.;Wheaton, Laura
通讯作者：
Wheaton, Laura
影响因子：
4.8
作者：
Kondejewski, LH;Lee, DL;Hodges, RS
通讯作者：
Hodges, RS
影响因子：
3.4
作者：
HALL, JE;VODYANOY, I;MARSHALL, GR
通讯作者：
MARSHALL, GR