Ab initio theory of helix↔coil phase transition
Frankfurt Institute for Advanced Studies, Ruth-Moufang Str. 1, 60438 Frankfurt am Main, Germany
Corresponding author: a email@example.com
Revised: 8 October 2007
Published online: 5 December 2007
In this paper, we suggest a theoretical method based on the statistical mechanics for treating the α-helix↔random coil transition in alanine polypeptides. We consider this process as a first-order phase transition and develop a theory which is free of model parameters and is based solely on fundamental physical principles. It describes essential thermodynamical properties of the system such as heat capacity, the phase transition temperature and others from the analysis of the polypeptide potential energy surface calculated as a function of two dihedral angles, responsible for the polypeptide twisting. The suggested theory is general and with some modification can be applied for the description of phase transitions in other complex molecular systems (e.g. proteins, DNA, nanotubes, atomic clusters, fullerenes).
PACS: 82.60.Fa – Heat capacities and heats of phase transitions / 87.15.He – Dynamics and conformational changes / 64.70.Nd – Structural transitions in nanoscale materials / 64.60.-i – General studies of phase transitions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007