Subject: phosphate solvation energies

From: [email-masked] (Howard Alper)
Date: Fri, 21 Apr 1995 12:20:18 -0500 (EDT)

Dr. Zhou,

  I was involved in lipid simulation research.  In particular, the group
I was in performed simulations of hydrated DMPC lipid monolayers and bilayers.
Among other quantities that we calculated was the solvation of the phosphate
and choline portion of the lipid headgroups.  The results are highly dependent
on the potential/force cutoffs used, since phosphate is charged, but using
cutoffs of effectively 30angstroms we obtained a solvation energy of -83.49
kcal/mole.  Computational requirements prevented using larger cutoffs, but the
infinite-cutoff result is most likely near the value quoted above.  One must
also keep in mind that the phosphate group is not isolated, but is part of the
lipid headgroup, along side other lipid molecules.  But -83.49 should give
you at least a reasonable starting estimate.  For more information you might
want to consult the following references:

H. E. Alper, D. Bassolino, and T. R. Stouch., J. Chem. Phys. 98, 9798 (1993).

H. E. Alper, D. Bassolino, and T. R. Stouch., J. Chem. Phys. 99, 5547 (1993).

  Howard Alper

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  Dr. Howard Alper
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