[AMBER] How to define center of mass for two separate residues in the restraint file?

From: Catein Catherine <askamber23.hotmail.com>
Date: Fri, 13 Aug 2010 11:04:09 +0800

Dear Sir/Madam,

 

I could like to define a distance restraint between residue4+residue5 and the drug. I want to define the center of mass for residue4+residue5 and drug.

 

I know how to define it if I only select one of the atoms from residue4 or residue20 or drug(residuenumber 100) as follows:

 

# distance restraint
&rst iat=4,100, r1=0.0, r2=10.0, r3=10.0, r4=100.0, rk2 =1.0, rk3 = 1., iresid=1,
ATNAM(1)='C1',
ATNAM(2)='C1' /

 

If I want to define the center of mass for the drug, I think I can change it to

 

# distance restraint
&rst iat=4,100, r1=0.0, r2=10.0, r3=10.0, r4=100.0, rk2 =1.0, rk3 = 1., iresid=1,
ATNAM(1)='C1',
ATNAM(2)='C1', 'H1','H2', 'H3','C2','C3'.....etc for all atoms in the drug /

 

However, how can I define the center of mass for residue4and20 as one end of the distance restraint?

 

# distance restraint
&rst iat=4,20,100, r1=0.0, r2=10.0, r3=10.0, r4=100.0, rk2 =1.0, rk3 = 1., iresid=1,
ATNAM(1)='C1',...all atoms in residue 4and20.
ATNAM(2)='C1', 'H1','H2', 'H3','C2','C3'.....etc for all atoms in the drug /

 

I found the it will mistook as an angle contraint, as I have three entry in "iat" now. How can I define which one of them properly?

 

Best regards and many thanks in advance,

 

PS. Thanks Jason for my previous question.

 

Cat


 
                                               
_______________________________________________
AMBER mailing list
AMBER.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber
Received on Thu Aug 12 2010 - 20:30:03 PDT
Custom Search