title: The folding of acetyl(Ala)28NH2 and acetyl(Ala)40NH2 extended strand peptides into antiparallel β-sheets. A density functional theory study of β-sheets with β-turns.
abstract: We report ONIOM calculations using B3LYP/D95** and AM1 on β-sheet formation from acetyl(Ala)(N)NH(2) (N = 28 or 40). The sheets contain from one to four β-turns for N = 28 and up to six for N = 40. We have obtained four types of geometrically optimized structures. All contain only β-turns. They differ from each other in the types of β-turns formed. The unsolvated sheets containing two turns are most stable. Aqueous solvation (using the SM5.2 and CPCM methods) reduces the stabilities of the folded structures compared to the extended strands.
authors.affiliation: Department of Chemistry, City University of New York - Hunter College and the Graduate School, New York 10065, United States.
authors.forename: Jorge
authors.initials: J
authors.lastname: Ali-Torres
authors.forename: J J
authors.initials: JJ
authors.lastname: Dannenberg
mesh_terms: D006860:Hydrogen Bonding; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013816:Thermodynamics
chemical_list: D010455:Peptides; C019529:polyalanine