AMBER: molecule drift out of water box?

From: Qiuting Hong <qiutinghong.gmail.com>
Date: Fri, 19 Sep 2008 16:39:42 -0700

Dear Amber users,

I am doing MD for a mouse ubiquitin, 1wgg, which has a long side chain. When
I solvate the protein, I try solvateoct TIP3PBOX 12.0 and
solvateoct TIP3PBOX 10.0. And I find out that the size of solute vdw
bounding box is same: 36.162, 30.853, 52.074. So, I decide to use TIP3PBOX
10.0 since it has less water molecules.

In the amber tutorial, it asks us to reimage all the water molecules into
the original box. So I did it, and I find out that a very small part of my
protein side chain drift into the vacuum after 1ns.

However, if I don't reimage the water molecules into the original box, the
whole protein is still in water. I am wondering whether or not my protein
drifts out of water box. Do I trust the reimaged trajectory or the original
trajectory?

If my protein do drift out ot the water box, how do I fix it? I think I need
to enlarge the water box, but both TIP3PBOX 12.0 and TIP3PBOX 10.0 give me
the same size of water box. I know that if I don't truncate the waterbox, I
won't have this problem. But I don't want to use so many water molecule in
the simulation.

I am using amber 9.
Can somebody help me?

Thank you.

Qiuting Hong

-----------------------------------------------------------------------
The AMBER Mail Reflector
To post, send mail to amber.scripps.edu
To unsubscribe, send "unsubscribe amber" (in the *body* of the email)
      to majordomo.scripps.edu
Received on Sun Sep 21 2008 - 05:08:54 PDT
Custom Search