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Hydration of an α‐Helical peptide: comparison of theory and molecular dynamics simulation
Author(s) -
García Angel E.,
Hummer Gerhard,
Soumpasis Dikeos Mario
Publication year - 1997
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/(sici)1097-0134(199704)27:4<471::aid-prot1>3.0.co;2-e
Subject(s) - molecular dynamics , helix (gastropod) , molecule , biomolecule , chemistry , chemical physics , potential of mean force , polar , biomolecular structure , density functional theory , computational chemistry , physics , statistical physics , thermodynamics , protein structure , quantum mechanics , ecology , biochemistry , organic chemistry , snail , biology
We present a statistical mechanical description of biomolecular hydration that accurately describes the hydrophobic and hydrophilic hydration of a model α‐helical peptide. The local density of water molecules around a biomolecule is obtained by means of a potential‐of‐mean‐force (PMF) expansion in terms of pair‐ and triplet‐correlation functions of bulk water and dilute solutions of nonpolar atoms. The accuracy of the method is verified by comparing PMF results with the local density and site‐site correlation functions obtained by molecular dynamics simulations of a model α‐helix in solution. The PMF approach quantitatively reproduces all features of the peptide hydration determined from the molecular dynamics simulation. Regions of hydrophobic hydration near the C α and C β atoms along the helix are well reproduced. The hydration of exposed polar groups at the N‐ and C‐termini of the helix are also well described by the theory. A detailed comparison of the local hydration by means of site‐site radial distribution functions evaluated with the PMF theory shows agreement with the molecular dynamics simulations. The formulation of this theory is general and can be applied to any biomolecular system. The accuracy, speed of computation, and local character of this theory make it especially suitable for studying large biomolecular systems. © 1997 Wiley‐Liss Inc.