Molecular recognition properties of acyclic cucurbiturils toward amino acids, peptides, and a protein
Molecular recognition properties of acyclic cucurbiturils toward amino acids, peptides, and a protein
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DOI：
10.1080/10610278.2019.1619737
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发表时间：
2019-05
影响因子：
3.3
通讯作者：
Sandra A. Zebaze Ndendjio;L. Isaacs
中科院分区：
文献类型：
--
作者：
Sandra A. Zebaze Ndendjio;L. Isaacs
本文报道了用~ 1HNMR和ITC研究1和2与19种氨基酸酰胺的结合。通过在C=O入口处留下阳离子残基的空腔内含物，R11和R2与芳香族或疏水残基结合。Ka值范围为102至>106 M−1，H-Phe-NH 2、H-Trp-NH 2和H-Tyr-NH 2显示亚微摩尔Kd值。β 1和β 2与双阳离子H-Lys-NH 2和H-Arg-NH 2紧密结合，它们是CB的不良客人[7]。比较1和2对氨基酸酰胺、N-乙酰基-氨基酸酰胺和氨基酸形式的苯丙氨酸的亲和力，发现去除NH3+与O=C和SO 3 −的静电相互作用需要3.8 kcal/mol，而引入不利的CO2−与O=C和SO 3 −的静电相互作用需要2.1 kcal/mol。β 1和β 2以低微摩尔亲和力与胰岛素结合。无环CB[n]显示出比CB[n]对更宽范围的N-末端氨基酸残基的高亲和力，这表明广泛的应用。图表摘要目录图表
ABSTRACT The binding of 1 and 2 toward 19 amino acid amides by 1H NMR and ITC is reported. Hosts 1 and 2 bind to aromatic or hydrophobic residues by cavity inclusion leaving the cationic residues at the C=O portals. Ka values range from 102 to >106 M−1 with H-Phe-NH2, H-Trp-NH2, and H-Tyr-NH2 displaying sub-micromolar Kd values. Hosts 1 and 2 bind tightly to dicationic H-Lys-NH2 and H-Arg-NH2 which are poor guests for CB[7]. Comparison of the affinity of 1 and 2 toward the amino acid amide, N-acetyl-amino-acid amide, and amino acid forms of Phe revealed that the removal of the NH3+ to O=C and SO3− electrostatic interactions costs 3.8 kcal/mol whereas the introduction of an unfavourable CO2− to O=C and SO3− electrostatic interactions costs 2.1 kcal/mol. Hosts 1 and 2 bind to insulin with low micromolar affinity. Acyclic CB[n] display high affinity toward a wider range of N-terminal amino acids residues than CB[n] which suggests a broad range of applications. Graphical Abstract Table of contents graphic