Andrei Iuliana M, Chen Wenzhang, Baaden Marc, Vincent Stéphane P, Barboiu Mihail
Institut Europeen des Membranes (IEM), Adaptive Supramolecular Nanosystems Group (NSA), University of Montpellier, ENSCM-CNRS, UMR 5635, 34095 Montpellier, France.
Department of Chemistry, Bio-Organic Chemistry Laboratory, University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.
J Am Chem Soc. 2023 Oct 11;145(40):21904-21914. doi: 10.1021/jacs.3c06335. Epub 2023 Sep 28.
Transport of water across cell membranes is a fundamental process for important biological functions. Herein, we focused our research on a new type of symmetrical saccharide rim-functionalized pillar[5]arene (PA-S) artificial water channels with variable pore structures. To point out the versatility of PA-S channels, we systematically varied the nature of anchoring/gate keepers d-mannoside, d-mannuronic acid, or sialic acid H-bonding groups on lateral pillar[5]arene (PA) arms, known as good membrane adhesives, to best describe the influence of the chemical structure on their transport activity. The control of hydrophobic membrane binding-hydrophilic water binding balance is an important feature influencing the channels' structuration and efficiency for a proper insertion into bilayer membranes. The glycosylated PA channels' transport performances were assessed in lipid bilayer membranes, and the channels were able to transport water at high rates (∼10-10 waters/s/channel within 1 order of magnitude as for aquaporins), serving as selective proton railways with total Na and K rejection. Molecular simulation substantiates the idea that the PAs can generate supramolecular pores, featuring hydrophilic carbohydrate gate-keepers that serve as water-sponge relays at the channel entrance, effectively absorbing and redirecting water within the channel. The present channels may be regarded as a rare biomimetic example of artificial channels presenting proton vs cation transport selectivity performances.
水跨细胞膜的运输是重要生物学功能的一个基本过程。在此，我们将研究重点聚焦于一种新型的具有可变孔结构的对称糖类边缘功能化柱[5]芳烃（PA-S）人工水通道。为了指出PA-S通道的多功能性，我们系统地改变了连接/守门基团d-甘露糖苷、d-甘露糖醛酸或唾液酸氢键基团在侧链柱[5]芳烃（PA）臂上的性质，这些基团是已知的良好膜黏附剂，以最好地描述化学结构对其运输活性的影响。控制疏水膜结合-亲水水结合平衡是影响通道结构形成以及有效插入双层膜的效率的一个重要特征。在脂质双层膜中评估了糖基化PA通道的运输性能，这些通道能够以高速率运输水（与水通道蛋白一样，在1个数量级内约为10-10个水分子/秒/通道），作为选择性质子通道，完全排斥Na和K。分子模拟证实了PA能够产生超分子孔的观点，其具有亲水性碳水化合物守门基团，在通道入口处充当水海绵中继器，有效地吸收并引导通道内的水。目前的通道可被视为呈现质子与阳离子运输选择性性能的人工通道的一个罕见仿生实例。
