[gmx-users] Langevin dynamics

[Alan Wilter Sousa da Silva]

I used LD but not in GMX.  The idea I employed is something like that:

A had a protein complexed with a substrate.  I want solvent, but my
box system created is very big.  So, I take a sphere embracing my whole
protein system with all solvent that can fit in and apply LD to a spheric
section region, lessing a smaller interior sphere under classic MD.
Moreover, the atoms under LD must be position restrained. Then, all 
atoms outside the exterior sphere are removed.

I don't know if GMX is able to do it, since it will involve a radical 
modification in topologies files.

See reference below for further details:

Stochastic molecular dynamics of peanut lectin PNA complex with T-antigen
disaccharide
 Caffarena ER, Grigera JR, Bisch PM
 JOURNAL OF MOLECULAR GRAPHICS & MODELLING 21 (3): 227-240 DEC 2002
 
Cheers,

On Thu, 31 Jul 2003, Anton Feenstra wrote:

> Jia-Lin Lo wrote:
> > Hi;
> >      I would like to know how do you perform LD with not explicit solvent.
> > Did gromacs provide implict solvent model? If not, how did you simulate
> > the protein with LD method.  How did you make gro and top files.
> > Thanks in advance.
> 
> I never used LD, but Berk Hess (my roommate then, reads this list too) did.
> AFAIR, he only used distance dependent dielectric. There are rumours
> about an implicit solvent model bein implemented in Vijay Pande's group
> (Stanford U, for the folding at home project), but AFAIK it hasn't been
> released (yet).
> 
> 
> 

-- 
-----------------------
Alan Wilter S. da Silva
-----------------------
 Laboratório de Física Biológica
  Instituto de Biofísica Carlos Chagas Filho
   Universidade do Brasil/UFRJ
    Rio de Janeiro, Brasil