On 9/23/13 10:23 AM, ABEL Stephane 175950 wrote:
Hello Justin,

Thank you for your response and your interest for my simulations ;) I am of course aware 
that the "primary" water model for the CHARMM is the TIP3(S)P model.

Since, I am mainly interested to the water dynamic around DOPC molecules in the 
context of the different water/DOPC mesophases (not data available, I currently 
doing the tests ;)) and that it is known that the TIP4P/2005 water model (it is 
the model, I want to use) reproduces better the water dynamic and structure 
than the TIP3P water model, I would like to test if the TIP4P/2005 water can be 
used in simulation of membranes. I am not aware that somebody have already done 
the test.

Finally, Justin, you are probably right here, the results will be probably not 
good as it is suggested by Pastor and MacKerell in their paper for TIP4P-EW 
water model [1], but I think that it is worth a test to confirm this in case of 
the TIP4P/2005. I am not the first one to ask this question in the context of 
simulations with the CHARMM force field (for protein, here [2]).

[1] www.ncbi.nlm.nih.gov/pmc/articles/PMC3133452/
[2]  Nutt, D. R.; Smith, J. C. Molecular Dynamics Simulations of Proteins: Can 
the Explicit Water Model Be Varied? J. Chem. Theory Comput. 2007, 3, 1550–1560.


It sounds like you're on the right track, at least knowing that a considerable amount of work has to be done to prove that the force field + water model combination is sound. Given that you're going to have to re-equilibrate the water anyway, I don't see why you have to start with TIP3P and try to hack it into becoming TIP4P; I would just strip the water and re-solvate.

-Justin

--
==================================================

Justin A. Lemkul, Ph.D.
Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 601
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalem...@outerbanks.umaryland.edu | (410) 706-7441

==================================================
--
gmx-users mailing list    gmx-users@gromacs.org
http://lists.gromacs.org/mailman/listinfo/gmx-users
* Please search the archive at 
http://www.gromacs.org/Support/Mailing_Lists/Search before posting!
* Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org.
* Can't post? Read http://www.gromacs.org/Support/Mailing_Lists

Reply via email to