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Salt effects on hydrophobic‐core formation in folding of a helical miniprotein studied by molecular dynamics simulations
Author(s) -
Yoda Takao,
Sugita Yuji,
Okamoto Yuko
Publication year - 2014
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/prot.24467
Subject(s) - salt bridge , molecular dynamics , chemistry , folding (dsp implementation) , salt (chemistry) , protein folding , chemical physics , ion , crystallography , contact order , native state , computational chemistry , organic chemistry , biochemistry , mutant , electrical engineering , gene , engineering
ABSTRACT We have investigated effects of salt ions on folding events of a helical miniprotein chicken villin headpiece subdomain HP36. Low concentrations of ions alter electrostatic interactions between charged groups of a protein and can change the populations of conformers. Here, we compare two data sets of folding simulations of HP36 in explicit water solvent with or without ions. For efficient sampling of the conformational space of HP36, the multicanonical replica‐exchange molecular dynamics method was employed. Our analyses suggest that salt alters salt‐bridging nature of the protein at later stages of folding at room temperature. Especially, more nonnative, nonlocal salt bridges are formed at near‐native conformations in pure water. Our analyses also show that such salt‐bridge formation hinders the fully native hydrophobic‐core packing at the final stages of folding. Proteins 2014; 82:933–943. © 2013 Wiley Periodicals, Inc.