Koert Ulrich
Fachbereich Chemie, Philipps-Universität Marburg, D-35032 Marburg, Germany.
Phys Chem Chem Phys. 2005 Apr 7;7(7):1501-6. doi: 10.1039/b418561g.
Various synthetic ion channels were derived from the gramicidin A beta-helix-lead structure. The ion transport through these channels was studied by single-channel current measurements in planar lipid bilayers. For asymmetric THF-gramicidin hybrids a selective insertion into the phospholipid bilayer was observed. Ion-selectivity could be achieved by the use of synthetic cyclohexyl-ether amino acids as channel building blocks. The balance between the desolvation energy and the binding energy inside the channel is discussed. For minigramicidins, the hydrophobic coupling of the channel with membranes of different thickness was studied by dwelltime analysis. A conformational switch of a double stranded beta-helix into a single stranded beta-helix was observed upon addition of Cs(+)-ions.
各种合成离子通道源自短杆菌肽A的β-螺旋先导结构。通过在平面脂质双分子层中进行单通道电流测量来研究离子通过这些通道的运输。对于不对称的四氢呋喃-短杆菌肽杂化物，观察到其选择性插入磷脂双分子层。通过使用合成的环己基醚氨基酸作为通道构建块可以实现离子选择性。讨论了通道内去溶剂化能与结合能之间的平衡。对于微型短杆菌肽，通过停留时间分析研究了通道与不同厚度膜的疏水偶联。加入Cs(+)离子后观察到双链β-螺旋向单链β-螺旋的构象转换。
