School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia.
J Phys Chem Lett. 2020 Oct 1;11(19):8152-8156. doi: 10.1021/acs.jpclett.0c02335. Epub 2020 Sep 15.
GALA is a 30-residue amphipathic peptide that self-assembles into multimeric transmembrane pores in a pH-dependent fashion. In this study, we characterize the size, multimeric structure, and cation selectivity of GALA pores in planar phospholipid bilayers using electrical impedance spectroscopy and molecular dynamics simulations. We demonstrate that in planar bilayers GALA pores are likely formed by six peptide monomers rather than eight to 12 monomers as previously reported for lipid vesicles. We further show that in planar bilayers, GALA pores exhibit previously unreported cation selectivity. We propose that the difference between the predicted pore structures in planar bilayers and lipid vesicles exemplifies the importance of phospholipid bilayer structural properties on the aggregation of transmembrane helical structures.
GALA 是一种由 30 个残基组成的两亲性肽，它以依赖 pH 的方式自组装成多聚体跨膜孔。在这项研究中，我们使用阻抗谱和分子动力学模拟技术来描述 GALA 孔在平面磷脂双层中的大小、多聚体结构和阳离子选择性。我们证明，在平面双层中，GALA 孔可能由六个肽单体形成，而不是以前报道的脂质体中的八个到十二个单体。我们进一步表明，在平面双层中，GALA 孔表现出以前未报道的阳离子选择性。我们提出，平面双层中预测的孔结构与脂质体之间的差异说明了磷脂双层结构特性对跨膜螺旋结构聚集的重要性。
