title: Computationally designed β-turn foldamers of γ-peptides based on 2-(aminomethyl)cyclohexanecarboxylic acid.
abstract: The γ-peptide β-turn structures have been designed computationally by the combination of chirospecific γ(2),(3)-residues of 2-(aminomethyl)cyclohexanecarboxylic acid (γAmc(6)) with a cyclohexyl constraint on the C(α) -C(β) bond using density functional methods in water. The chirospecific γAmc(6) dipeptide with the (2S,3S)-(2R,3R) configurations forms a stable turn structure in water, resembling a type II' turn of α-peptides, which can be used as a β-turn motif in β-hairpins of Ala-based α-peptides. The γAmc(6) dipeptide with homochiral (2S,3S)-(2S,3S) configurations but different cyclohexyl puckerings shows the capability to be incorporated into one of two β-turn motifs of gramicidin S. The overall structure of this gramicidin S analogue is quite similar to the native gramicidin S with the same patterns and geometries of hydrogen bonds. Our calculated results and the recently observed results may imply the wider applicability of chirospecific γ-peptides with a cyclohexyl constraint on the backbone to form various peptide foldamers.
authors.affiliation: Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea. ykkang@chungbuk.ac.kr
authors.forename: Young Kee
authors.initials: YK
authors.lastname: Kang
authors.forename: Byung Jin
authors.initials: BJ
authors.lastname: Byun
mesh_terms: D006096:Gramicidin / Q000737:chemistry; D009842:Oligopeptides / Q000737:chemistry*; D011487:Protein Conformation; D013237:Stereoisomerism; D014148:Tranexamic Acid / Q000031:analogs & derivatives* / Q000737:chemistry*
chemical_list: D009842:Oligopeptides; D006096:Gramicidin; D014148:Tranexamic Acid