Comprehensive conformational analysis of N-acetyl-l-tryptophane-N-methylamide. An ab initio and DFT study

Autor:	José Abel Bombasaro, Ricardo D. Enriz, Ana M. Rodríguez
Rok vydání:	2005
Předmět:	Crystallography Stereochemistry Chemistry Helix Ab initio Potential energy hypersurface Methylamide Physical and Theoretical Chemistry Condensed Matter Physics Biochemistry Conformational isomerism Polyproline helix Peptide Conformation
Zdroj:	Journal of Molecular Structure: THEOCHEM. 724:173-184
ISSN:	0166-1280
DOI:	10.1016/j.theochem.2004.11.040
Popis:	A comprehensive conformational analysis has been carried out on N-acetyl- l -tryptophane-N-methylamide. The complete set of minima has been located on the Potential Energy Hypersurface (PEHS) using ab initio (RHF/6-31G(d)) and DFT (B3LYP/6-31G(d)) calculations. Previous ab initio structure determinations at the RHF/3-21G level of theory resulted in 36 different structures. In the present work, a total of 35 and 34 different conformations were obtained at RHF/6-31G(d) and DFT (B3LYP/6-31G(d)) levels, respectively. Diamide conformers, similar to structural building units of the right-handed helix (αL) as well as of polyproline II type structures (eL) were found. However, C 7 eq (γL) and extended C5 (βL) conformations were the preferred forms for this compound. Sidechain structural (i.e. χ1 and χ2 conformer interconversions) are also discussed in this paper.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ead78e39f632c8e39a0af3c60a0ac90c https://doi.org/10.1016/j.theochem.2004.11.040 Zobrazit plný text záznamu Full Text from ScienceDirect