[gmx-users] MD at high temperature

[K.A. Feenstra]

MOLTENI at unisi.it wrote:
> 
> Hi
> 
> I have a question: is it useful to perform a MD simulation at high
> temperature in order to "speed up" the evolution of the system? And
> which are the possible drawbacks?

It can be. The drawbacks are that you might get into conformations
that normally would not be accessible, and are actualy not helpful
(e.g. partially unfolded structures).

> At which temperature should I run a simulation to sample more
> efficiently the conformational space, without getting non-physical
> results (such as partial unfolding of the peptide)?

I don't think one can say anything about this in the general case.
The effects can be quite subtle, as in the case of a b-amino-peptide
(see articles by X. Daura and/or W.F. van Gunsteren), where a 20-40
degree increase in temperatures shifts the equilibrium from >70%
folded to >70% unfolded (or similar, don't know the details exactly).
On the other hand, I've simulated a protein (HPr) at >=600K, which
remained perfectly stable.


-- 
Groetjes,

Anton
 ________ ___________________________________________________________
|        | Anton Feenstra                                            |
| .      | Dept. of Pharmacochemistry - Vrije Universiteit Amsterdam |
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