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Date: Tue, 5 Feb 2002 19:16:40 +0800
From: songyunlong <songyunlong*- at -*263.net>
To: "chemistry-: at :-ccl.net" <chemistry-: at :-ccl.net>
Subject: Charmm22 force field for DNA
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Dear Computational Chemsitry Listers:
Recently,I met with a difficult problem.I want to run a MCSS job to investigate the active site of a protein-DNA complex.However,the MCSS job requires the force field must be charmm22 force field. Then I assign the charmm22 force field to the protein-DNA complex,however,some nitrogen atoms of DNA,such as N3,N7, are not parameterized by charmm22 force field.I wonder whether DNA has been parameterized by charmm22 force field.In my opinion,as a famous macromolecular force field,CHARMM should have parmaterized for DNA as well as protein.How can I settle this problem? 
How can I parameterize DNA with charmm22 force field? Could you please kindly give me any suggestions on this problem?

Best wishes to you!


Song Yunlong,Ph.D
~~~~~~~~~~~~~~~~~~~~~~~~~~
Dept of med chem
School of pharmacy
Sec Mil Med Univ
Guohe Road,325
Shanghai,200433
E-mail:songyunlong $#at#$ 263.net
~~~~~~~~~~~~~~~~~~~~~~~~~~