了解和控制磷脂双层中的肽折叠体构象是其用作膜中分子信息中继的关键一步。为此,我们开发了一种新的19 F“报告者”标签,并将其附加到动态肽折叠器上。 ( R )-1-(三氟甲基)乙基酰胺基(( R )-TFEA)报道分子连接至α-氨基-异丁酸(Aib)折叠体的C末端。晶体学证实折叠体采用3 ×10螺旋构象。有机溶剂中的变温 (VT) NMR 光谱表明 ( R )-TFEA 报道分子对P螺旋性具有内在偏好,但整体螺旋方向由 N 末端的手性“控制器”主导。 CF 3共振的19 F NMR化学位移与不同N端基团在溶液中诱导M或P螺旋的能力相关。在双层中,也发现了类似的相关性。含有相同家族 ( R )-TFEA 标记的折叠体的小单层囊泡 (SUV) 悬浮液的溶液19 F NMR 光谱显示出较宽但可分辨的19 F 共振,每个化学位移反映了它们在有机溶剂中的相对位置。这些研究表明,磷脂双层中的折叠体构象
Quantifying End-to-End Conformational Communication of Chirality through an Achiral Peptide Chain
作者:Jonathan Clayden、Alejandro Castellanos、Jordi Solà、Gareth A. Morris
DOI:10.1002/anie.200901892
日期:2009.7.27
Successful communication: Two diastereotopic protons more than 60 bonds from the nearest chiral center appear as an AB system, showing that the intervening structure is a well‐ordered helix. Decay of anisochronicity quantifies the linear persistence of a helix of achiral amino acids: as little as 3.5 % of the chiral influence is lost with each additional achiral residue.
Conformational cooperativity between helical domains of differing geometry in oligoamide–oligourea foldamer chimeras
作者:Julien Maury、Bryden A. F. Le Bailly、James Raftery、Jonathan Clayden
DOI:10.1039/c5cc02995c
日期:——
Two foldamer domains of different classes (urea and amide) remain in conformational communication, and adopt a well-defined global structure in solution, provided the interdomain hydrogen-bonds are suitably orientated.
Bis-pyrene probes of foldamer conformation in solution and in phospholipid bilayers
作者:Francis G. A. Lister、Natasha Eccles、Sarah J. Pike、Robert A. Brown、George F. S. Whitehead、James Raftery、Simon J. Webb、Jonathan Clayden
DOI:10.1039/c8sc02532k
日期:——
requires sensitive probes of conformation. Here we describe the design, synthesis and characterization of bis(pyrene) probes that report conformational changes in membrane-active dynamic foldamers. The probes were designed to distinguish between left-handed (M) and right-handed (P) screw-sense conformers of 310-helical α-aminoisobutyric acid (Aib) peptide foldamers, both in solution and in bilayer membranes
探索膜相中合成分子的详细结构特征需要灵敏的构象探针。在这里,我们描述了报告膜活性动态折叠体中构象变化的双(芘)探针的设计、合成和表征。探针设计用于区分溶液和双层膜中的 3个 10-螺旋 α-氨基异丁酸 (Aib) 肽折叠体的左旋 ( M ) 和右旋 ( P ) 螺旋式构象异构体。合成了几种不同的双(芘)探针并将其连接到在N端具有不同手性残基的 Aib 四聚体的 C 端,这些残基在 310-螺旋。易于合成且方便掺入的N-乙酰基-1,2-双(芘-1'-基)乙二胺探针被证明具有最佳性能。在溶液中,折叠体螺旋感的变化导致该构象报告者的准分子/单体荧光发射( E / M)比率发生显着变化,X射线晶体学显示相反的螺旋感产生非常不同的芘间距离记者。在双层中,这种方便且灵敏的荧光报告器首次允许研究天然磷脂的手性如何影响折叠体构象。