[apbs-users] The surface charge of soluble proteins and its meaning for protein-solvent interaction

[Lincong Wang]

Dear All,
     I am Lincong Wang who as all of you are is interested in the
  electrostatic interactions of biomolecules. Recently i have
  performed a large scale statistical analysis of the surface charges
  of soluble proteins and discovered that they all (or nearly all since the definition of a soluble protein is NOT exact)
  have net negative surface charge and they behave as capacitors in
  solution.  The results will be presented in 2 papers with a draft
  (~95% complete) of the first paper submitted to arXiv
  (https://arxiv.org/abs/1605.01155). Any comments on the paper are
  very welcome.

Many thanks and looking forward to hearing from you.

Sincerely,
Lincong Wang

P.S. The title and abstract of the draft.
  


The contributions of surface charge and geometry to protein-solvent interaction
Lincong Wang

    To better understand protein-solvent interaction we have analyzed
    a variety of physical and geometrical properties of the
    solvent-excluded surfaces (SESs) over a large set of soluble
    proteins with crystal structures. We discover that all have net
    negative surface charges and permanent electric dipoles. Moreover
    both SES area and surface charge as well as several physical and
    geometrical properties defined by them change with protein size
    via well-fitted power laws. The relevance to protein-solvent
    interaction of these physical and geometrical properties is
    supported by strong correlations between them and known
    hydrophobicity scales and by their large changes upon protein
    unfolding. The universal existence of negative surface charge and
    dipole, the characteristic surface geometry and power laws reveal
    fundamental but distinct roles of surface charge and SES in
    protein-solvent interaction and make it possible to describe
    solvation and hydrophobic effect using theories on anion solute in
    protic solvent. In particular the great significance of surface
    charge for protein-solvent interaction suggests that a change of
    perception may be needed since from solvation perspective folding
    into a native state is to optimize surface negative charge rather
    than to minimize the hydrophobic surface area.