title: Folding of an Ala-Ala-Ala tripeptide into a beta-turn via hydrophobic encapsulation.
abstract: An Ac-Ala-Ala-Ala-NH2 tripeptide was folded into a beta-turn structure even in water through hydrophobic binding by a self-assembled porphyrin cage. The turn conformation of the bound peptide was fully assigned from NOESY measurements and was strongly supported by molecular dynamics simulation. Single mutation experiments and molecular modeling also suggested that CH-pi interactions between methyl groups of Ala residues and porphyrin ligands were important for the stabilization of the turn conformation. Furthermore, we observed the induction of a beta-hairpin structure by encapsulation of a heptapeptide, Ac-Gly-Gly-Ala-Ala-Ala-Gly-Gly-NH2, possessing Ala-Ala-Ala sequence at the middle.
authors.affiliation: Department of Applied Chemistry, School of Engineering, The University of Tokyo, CREST, Japan Science and Technology Agency (JST), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Tashiro
authors.forename: Masahide
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Makoto
authors.initials: M
authors.lastname: Fujita
mesh_terms: D000409:Alanine / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D009842:Oligopeptides / Q000737:chemistry*; D011487:Protein Conformation; D017510:Protein Folding
chemical_list: D009842:Oligopeptides; D000409:Alanine