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Ab Initio MP2 and Density Functional Theory Computational Study of AcAlaNH 2 Peptide Hydration: A Bottom‐Up Approach
Author(s) -
Lanza Giuseppe,
Chiacchio Maria A.
Publication year - 2014
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201402222
Subject(s) - density functional theory , ab initio , top down and bottom up design , computational chemistry , ab initio quantum chemistry methods , chemistry , chemical physics , materials science , molecule , computer science , organic chemistry , software engineering
AcAlaNH 2 ⋅ n H 2 O ( n =1–13) complexes have been proposed as models to account for water solvent effects on the molecular properties of N ‐acetyl‐ L ‐alanine amide. Ab initio computations are planned to evaluate peptide–water interactions and to provide a means for approximating relative effects of the short‐range many‐body interactions arising in real solution without introducing any external parameters intended to quantify empirical or semiempirical potential‐energy functions. The present bottom‐up approach reveals the formation of compact ring clusters of water molecules strongly bonded to peptidic polar groups throughout hydrogen bonds. The explicit coordination of water molecules around the peptide renders the fully extended (FE) and polyproline II (PPII) conformers more stable with respect to the 3 10 helix or γ turn. The alternance of donor and acceptor groups on both sides of the FE and PPII conformers allows for synergy and extensive H‐bonding.