Proulx Caroline, Lubell William D
Département de Chimie, Université de Montréal, C.P. 6128, Succursale Center-Ville, Montréal, QC H3C 3J7, Canada.
Biopolymers. 2014 Jan;102(1):7-15. doi: 10.1002/bip.22327.
N-Amino-imidazolin-2-ones, a new class of turn mimics onto which side chains of different amino acids may be added conveniently, have been analyzed by X-ray crystallography. 4-Methyl and 4-benzyl N-amino-imidazolin-2-one tetrapeptide models 2 and 3 were examined to study the influence of the 4-position substituent on turn conformation and the chi dihedral angle of the neighbouring C-terminal residue side-chain. The nature of the 4-position substituent caused substantial effects on the ψ(i + 2) main chain and C-terminal Phe χ(1) side-chain dihedral angle values, giving a preference for β- and γ-turn conformers for the methyl- and benzyl-substituted imidazolin-2-ones, respectively. Conformational analysis in the solid state has provided insight to guide application of N-amino-imidazolin-2-ones in peptide mimicry.
N-氨基咪唑啉-2-酮是一类新型的转角模拟物，不同氨基酸的侧链可以方便地连接到其上，已通过X射线晶体学进行了分析。研究了4-甲基和4-苄基N-氨基咪唑啉-2-酮四肽模型2和3，以研究4-位取代基对转角构象和相邻C端残基侧链的χ二面角的影响。4-位取代基的性质对ψ(i + 2)主链和C端苯丙氨酸χ(1)侧链二面角值产生了实质性影响，甲基取代的咪唑啉-2-酮分别优先形成β-转角和γ-转角构象。固态构象分析为指导N-氨基咪唑啉-2-酮在肽模拟中的应用提供了见解。
