Paper Info
Title
Toward a rational design of -peptide structures
Abstract
Intrinsic: conformational characteristics of beta-peptides built up from simple achiral and chiral P-amino acid residues (i.e., HCO-beta-Ala-NH2, HCO-beta-Abu-NH2) were studied using quantum chemical calculations and H-1-NMR spectroscopy. A conformer-based systematic and uniform nomenclature was introduced to differentiate conformers. Geometry optimizations were performed on all homoconformers of both HCO-(beta-Ala)k-NH2 and HCO-(beta-AbU)(k)-NH2 (1 <= k <= 6) model systems at the RHF/3-21G and RHF/6-311+ +G(d, p) levels of theory. To test for accuracy and precision, additional. computations were carried out at several levels of theory [e.g., RHF/6-31G(d), and B3LYP/6-311+ +G(d, p)]. To display the folding preference, the relative stability of selected conformers as function of the length of the polypeptide chain was determined. Ab initio population distribution of hexapeptides and the conformational ensemble of synthetic models composed of beta-Ala and beta-Abu studied using H-1-NMR in different solvents were compared at a range of temperatures. Helical preference induced by various steric effects of nonpolar side chains was tested using higher level ab initio methods for well-known model systems such as: HCO-(beta-HVal-beta-HAla-beta-HLeu)(2)-NH2, HCO-(ACHC)(6)-NH2, HCO-(trans-ACPC)(6)-NH2, and HCO-(cis-ACPC)(6)-NH2. The relative stabilities determined by theoretical methods agreed well with most experimental data, supporting the theory that the local conformational preference influenced by steric effects is a key determining factor of the global fold both in solution and in the gas phase.
Year
DOI
Venue
2006
10.1002/jcc.20299
JOURNAL OF COMPUTATIONAL CHEMISTRY
Keywords
DocType
Volume
beta-peptide,secondary structure,ab initio,DFT,geometry optimization,NMR
Journal
27
Issue
ISSN
Citations 
1
0192-8651
0
PageRank 
References 
Authors
0.34
0
3
Name
Order
Citations
PageRank
Tamás Beke101.01
Csaba Somlai200.34
András Perczel33916.63