title: Chain-length-dependent helical motifs and self-association of beta-peptides with constrained side chains.
abstract: Homo-oligomers constructed by using trans-2-aminocyclohexanecarboxylic acid monomers without protecting groups were studied. Both ab initio theory and NMR measurements showed that the tetramer tends to adopt a 10-helix motif, while the pentamer and hexamer form the known 14-helix. It was concluded that the conformationally constrained backbone is flexible enough to afford both 10-helical and 14-helical motifs, this observation in turn providing evidence of the true folding process. Self-association of the helical units was also detected, and the results of variable-temperature diffusion NMR measurements strongly suggested the presence of helical bundles in methanol solution.
authors.affiliation: Institute of Pharmaceutical Chemistry and Department of Medical Chemistry, University of Szeged, P.O. Box 121, H-6701 Szeged, Hungary.
authors.forename: Anasztázia
authors.initials: A
authors.lastname: Hetényi
authors.forename: István M
authors.initials: IM
authors.lastname: Mándity
authors.forename: Tamás A
authors.initials: TA
authors.lastname: Martinek
authors.forename: Gábor K
authors.initials: GK
authors.lastname: Tóth
authors.forename: Ferenc
authors.initials: F
authors.lastname: Fülöp
mesh_terms: D002942:Circular Dichroism; D003509:Cyclohexanecarboxylic Acids / Q000737:chemistry*; D003514:Cyclohexylamines / Q000737:chemistry*; D003903:Deuterium; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D009842:Oligopeptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013816:Thermodynamics
chemical_list: D003509:Cyclohexanecarboxylic Acids; D003514:Cyclohexylamines; D009842:Oligopeptides; C103271:2-aminocyclohexanecarboxylic acid; D003903:Deuterium