English

Entropy associated with conformation and density fluctuations in biomolecular solutions

Statistical Mechanics 2023-03-02 v1

Abstract

Microscopic formula to describe the entropy of biomolecular solutions are derived based on the Gibbs formula of entropy, and the generalized Langevin theory combined with the RISM/3D-RISM theory. Two formula are derived: one is concerned with the conformational fluctuation of a biomolecule, and the other with the density fluctuation of solvent around a solute. The formula derived for the entropy associated with the conformational fluctuation is where N is the number of atoms in the solute, and A is the determinant of the inverse of the variance-covariance matrix of conformational fluctuation. The formula for the entropy of solvent at a pair of positions around a solute is also derived to be, where n is the number of atoms in a solvent molecule, and B is essentially the determinant of the matrix of the density-pair-correlation functions. The entropy at a local position r may be obtained by integrating the expression by over the entire volume of the system. The feasibility of the calculation to find the entropies is discussed.

Keywords

Cite

@article{arxiv.2303.00278,
  title  = {Entropy associated with conformation and density fluctuations in biomolecular solutions},
  author = {Fumio Hirata},
  journal= {arXiv preprint arXiv:2303.00278},
  year   = {2023}
}