Dear AMBER users: 
Hi, I'm trying to perform a short MD in AMBER7 and I  
would like to know if it is possible to do such simulation  
holding a part of my structure fixed (ntr=1) and including  
NMR distance restraints (nmropt=1) for another part of  
the structure, at the same time. I tried different input  
protocols including both requirements but it doesn't  
seem to work. Either maintains part of the structure rigid 
(and  doesn't read the nmr distance restraints) or read 
the  NMR distance restraints but doesn't keep the other 
bit of  the molecule fixed. 
The typical protocol I used is: 
 &cntrl 
  igb = 1, 
  ntb = 0, 
  ntp = 0, 
  ntt = 1, 
  temp0 = 300.0, 
  tempi = 0.0, 
  nstlim = 20000, 
  dt = 0.001, 
  ntwx = 500, 
  ntwv = 500, 
  ntpr = 500, 
  ntwe = 500, 
  imin = 0, 
  cut = 99.0, 
  ntr = 1, 
  nmropt = 1, 
  saltcon = 0.2, 
  gbsa = 1, 
 &end 
Group input for restrained atoms 
 5.0 
RES 3 42 
END 
END 
  &wt type = 'END' 
 &end  
 DISANG = phn.disang 
END 
In the case I use this protocol the MD will be done only  
reading the NMR restraints but NOT keeping part of my  
molecule fixed (like it is not reading ntr=1...) 
Any ideas?? 
Thanks a lot 
Martin 
-----------------------------------------------------------------------
The AMBER Mail Reflector
To post, send mail to amber.scripps.edu
To unsubscribe, send "unsubscribe amber" to majordomo.scripps.edu
Received on Mon May 10 2004 - 10:53:01 PDT