Electron density redistribution accounts for half the cooperativity of alpha helix formation

TitleElectron density redistribution accounts for half the cooperativity of alpha helix formation
Publication TypeJournal Article
Year of Publication2006
AuthorsMorozov, A. V., Tsemekhman K., & Baker D.
JournalThe journal of physical chemistry. B
Volume110
Issue10
Pagination4503-5
Date Published2006 Mar 16
ISSN1520-6106
KeywordsAlgorithms, Computer Simulation, Dimerization, Electrons, Hydrogen Bonding, Models, Chemical, Models, Molecular, Peptides, Primary Publication, Protein Structure, Secondary, Quantum Theory, Static Electricity
Abstract

The energy of alpha helix formation is well known to be highly cooperative, but the origin and relative importance of the contributions to helical cooperativity have been unclear. Here we separate the energy of helix formation into short range and long range components by using two series of helical dimers of variable length. In one dimer series two monomeric helices interact by forming hydrogen bonds, while in the other they are coupled only through long range, primarily electrostatic interactions. Using Density Functional Theory, we find that approximately half of the cooperativity of helix formation is due to electrostatic interactions between residues, while the other half is due to nonadditive many-body effects brought about by redistribution of electron density with helix length.

Alternate JournalJ Phys Chem B
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