Subject: solvation

From: [email-masked]
Date: Thu, 26 Sep 2002 10:06:44 +0200

Since some years, we studied non-covalent interactions (especially
H-bond, stacking and cation pi) at the interface between protein and
nucleobase (DNA or ligand). And performed, ab initio quantum mechanics
energy calculations .
Actually, we focussed on cation-pi interactions between a charged amino
acid (such as Arg or Lys) and an aromatic ring of nucleic acid base
(such as Adenine).
However, until today, most of the calculations have been performed in
vacuum and the transposition of vacuum energy values to energy values in
water
can entail modifications in the energy ranking.

Recently, I try to use the polarizable continuum model (PCM) available
in Gaussian 98 Revision A.7, but surprising results have been obtained
(the interaction ernergie is positiv).

I have also used the mixed continuum-discrete solvation methods (ref
JACS 2002
Mennucci). But severe discontinuities are observed along the path
(physically unreasonable ???).

The SM module included in Spartan gave also strange results....

====I would like to know if someone has already used those models for
studying non convalent interactions.===
...and could help me ???

best & take care

Biot C.

-- 
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Dr. BIOT Christophe
Ingenierie Biomoleculaire, CP 165/64
Universite Libre de Bruxelles
50, Av. F. Roosevelt
B-1050 Bruxelles
Belgique
Phone: 32-2-650 3001
Fax:   32-2-650 3606
E-mail:[email-masked]
http://babylone.ulb.ac.be/~christophe/
http://www.ulb.ac.be/rech/inventaire/unites/ULB163.html
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