1H NMR studies quantify the abilities of achiral amino acids to communicate a left-handed screw-sense preference from one helical Aib4 domain to another: certain quaternary amino acids (e.g. Ac6c) act as effective conductors of conformational preference while others (e.g. diphenylglycine) acts as insulators.
Engineering the Structure of an N-Terminal β-Turn To Maximize Screw-Sense Preference in Achiral Helical Peptide Chains
作者:Matteo De Poli、Liam Byrne、Robert A. Brown、Jordi Solà、Alejandro Castellanos、Thomas Boddaert、Romina Wechsel、Jonathan D. Beadle、Jonathan Clayden
DOI:10.1021/jo500714b
日期:2014.5.16
preference are induced by bulky chiral tertiary amino acids carrying amide protecting groups or by chiral quaternary amino acids carrying carbamate protecting groups. Tertiary l-amino acids at the N-terminus of the oligomer induce a left-handed screwsense, while quaternary l-amino acids induce a right-handed screwsense. A screw-sense preference may also be induced from the second position of the chain
Molecular Recognition by Zn(II)‐Capped Dynamic Foldamers
作者:Natasha Eccles、Flavio della Sala、Bryden A. F. Le Bailly、George F. S. Whitehead、Jonathan Clayden、Simon J. Webb
DOI:10.1002/open.201900362
日期:2020.3
α‐aminoisobutyric acid (Aib) foldamers bearing Zn(II)‐chelating N‐termini have been synthesized and compared with a reported Aib foldamer that has a bis(quinolinyl)/mono(pyridyl) cap (BQPA group). Replacement of the quinolinyl arms of the BQPA‐capped foldamer with pyridyl gave a BPPA‐capped foldamer, then further replacement of the linking pyridyl with a 1,2,3‐triazole gave a BPTA‐capped foldamer. Their ability
合成了两个带有Zn(II)螯合N-末端的α-氨基异丁酸(Aib)折叠剂,并与已报道的具有双(喹啉基)/单(吡啶基)帽的BibPA折叠剂(BQPA组)进行了比较。用吡啶基取代BQPA封顶的折叠子的喹啉基臂得到BPPA封顶的折叠子,然后用1,2,3-三唑进一步取代连接的吡啶基得到BPTA封顶的折叠子。测量了它们将手性信息从在N末端与Zn(II)结合的羧酸酯传递到C末端构象偏好的基于甘氨酰胺的NMR报告分子的能力。喹啉基臂的重要性显而易见,因为带有吡啶基臂的折叠剂无法报告乙腈中手性羧酸盐的存在。低溶解度,X射线晶体学和11 H NMR光谱表明,折叠子之间的相互作用抑制了羧酸盐的结合。但是,将溶剂改为甲醇表明在低温下可以观察到BPTA封盖的折叠剂的Zn(II)配合物的手性信息的端到端传递。
End-to-end conformational communication through a synthetic purinergic receptor by ligand-induced helicity switching
作者:Robert A. Brown、Vincent Diemer、Simon J. Webb、Jonathan Clayden
DOI:10.1038/nchem.1747
日期:2013.10
The long-range communication of information, exemplified by signal transduction through membrane-bound receptors, is a central biochemical function. Reversible binding of a messenger ligand induces a local conformational change that is relayed through the receptor, inducing a chemical effect typically several nanometres from the binding site. We report a synthetic receptor mimic that transmits structural information from a boron-based ligand binding site to a spectroscopic reporter located more than 2Â nm away. Reversible binding of a diol ligand to the N-terminal binding site induces a screw-sense preference in a helical oligo(aminoisobutyric acid) foldamer, which is relayed to a reporter group at the remote C-terminus, communicating information about the structure and stereochemistry of the ligand. The reversible nature of boronate esterification was exploited to switch the receptor sequentially between left- and right-handed helices, while the exquisite conformational sensitivity of the helical relay allowed the reporter to differentiate even between purine and pyrimidine nucleosides as ligands. Biological receptors communicate information through ligand-induced conformational changes. A synthetic receptor with a boron-containing binding site that can selectively and reversibly complex a ligand (such as a purine nucleoside) is shown to function in a similar fashion. The resulting conformational change is relayed through the receptor, communicating structural information about the ligand to a spectroscopic reporter more than 2 nm away.
以通过膜结合受体的信号转导为例的长距离信息通信是一项重要的生化功能。信使配体的可逆结合引起局部构象变化,该变化通过受体传递,通常在距结合位点几纳米的地方引起化学效应。我们报道了一种合成受体模拟物,它将结构信息从基于硼的配体结合位点传输到位于 2 nm 以上的光谱报告基因。二醇配体与 N 端结合位点的可逆结合会在螺旋寡聚(氨基异丁酸)折叠体中诱导螺旋感应偏好,该折叠体被传递到远程 C 端的报告基团,传达有关结构和立体化学的信息配体的。利用硼酸酯化的可逆性质,将受体在左手螺旋和右手螺旋之间顺序切换,而螺旋中继的精致构象敏感性使报告者甚至能够区分作为配体的嘌呤和嘧啶核苷。 生物受体通过配体诱导的构象变化来传递信息。具有含硼结合位点的合成受体可以选择性地、可逆地与配体(例如嘌呤核苷)复合,以类似的方式发挥作用。由此产生的构象变化通过受体传递,将配体的结构信息传递给 2 nm 以外的光谱报告分子。
Induction of Unexpected Left-Handed Helicity by an N-Terminal L-Amino Acid in an Otherwise Achiral Peptide Chain
作者:Robert A. Brown、Tommaso Marcelli、Matteo De Poli、Jordi Solà、Jonathan Clayden
DOI:10.1002/anie.201107583
日期:2012.2.6
Peptide helices containing L‐amino acids are typically right‐handed. Exceptions are peptide helices containing the achiral amino acids 2‐aminoisobutyric acid and glycine with a single chiral amino acid at the N terminus. These helices are left‐handed when the N‐terminal residue is a common tertiary proteinogenic amino acid, such as L‐valine (see picture, left), but right‐handed when the N‐terminal