Re: [AMBER] CU library file

From: Matias Machado <mmachado.pasteur.edu.uy>
Date: Thu, 13 Jun 2019 12:38:30 -0300 (UYT)

Dear Fabian,

That's because leaprc.water.tip3p by default loads library "atomic_ions.lib" and parameters "frcmod.ionsjc_tip3p", "frcmod.ions234lm_126_tip3p" among water stuff...

Check the header of leaprc.water.tip3p:

#
# Load water and ions for TIP3P + Joung-Chetham monovalent ions
# + Li/Merz highly charged ions (+2 to +4, 12-6 normal usage set)
#

Best,

Matias

------------------------------------
PhD.
Researcher at Biomolecular Simulations Lab.
Institut Pasteur de Montevideo | Uruguay
[http://pasteur.uy/en/labs/biomolecular-simulations-laboratory]
[http://www.sirahff.com]
"
----- Mensaje original -----
De: "Fabian Glaser" <fabian.glaser.gmail.com>
Para: "AMBER Mailing List" <amber.ambermd.org>
CC: "Fabian Glaser" <fabian.glaser.gmail.com>
Enviados: Jueves, 13 de Junio 2019 12:09:25
Asunto: [AMBER] CU library file

Dear experts,

I am trying to prepare a protein-DNA-copper complex, regarding the metals, a Cu+2 and Mg+2 are included in my input pdb, I followed the instructions of tutorial 20 for the non-bonded metals, obtained a CU.lib file, loaded it as loadoff CU.lib and worked on tleap. But then, I removed this line which is reading the CU.lib, and still tleap works….

I am puzzled here, I thought this CU.lib is necessary for tleap to obtain the right parameters of this specific Cu+2 metal type. I am probably wrong?
Why is then still working without the library file?
Is the tip3p force field including those parameters for Cu+?
Am I doing something completely wrong?

This is my input file, as I said it works with or without the loadoff lines for CU or MG (both of them in my pdb).

Thanks!!

source leaprc.protein.ff14SB
source leaprc.water.tip3p
source leaprc.gaff
source leaprc.DNA.OL15 # DNA force field
source leaprc.phosaa10 # Parameters for phosphorylated amino acids

set default PBradii mbondi3

loadAmberParams frcmod.ionsjc_tip3p # Joung/Cheatham ion parameters for TIP3P water

loadoff CU.lib
CU = loadpdb CU.4amber.pdb #Load the PDB file


loadamberparams FC5_SP2.ante.frcmod
LIG = loadmol2 FC5_SP2.ante.mol2

REC = loadpdb 2XKK.clean.3.pdb # load PDB REC


loadoff MG.lib # MG library

COM = combine {REC LIG CU}

savepdb COM 2XKK.tleap.COM.dry.pdb
saveamberparm COM 2XKK.tleap.COM.dry.prmtop 2XKK.tleap.COM.dry.rst7


Best,

Fabian

Fabian Glaser PhD

Head of the Structural Bioinformatics section
Bioinformatics Knowledge Unit - BKU
The Lorry I. Lokey Interdisciplinary Center for Life Sciences and Engineering
Technion - Israel Institute of Technology, Haifa, Israel
Web http://bku.technion.ac.il/
Tel +972 (0) 4 8293701

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Received on Thu Jun 13 2019 - 09:00:04 PDT
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