macromodel and GRASP questions



 Hello CCLer's,
 	macromodel question: I'm optimising a batchmin com file at the moment
 that does a monte carlo conformational search.  The structures I'm
 looking at are peptides, so I would like to use a torsion selection
 function to favor random torsion angles near to the trans and cis minima
 of the peptide bonds.  Is there a way to set up the opcode MCTS to do
 this? Or some other way?
 	GRASP question: Having some problems with display of dipole moments.  I
 read in a pdb file and set full crg, calculate and display the dipole
 moment... no problems.  I repeat this on the second pdb file... no
 problems, but when I read in the third pdb file and calculate the dipole
 moment, the first protein's dipole moment shifts.  I haven't tried
 reading in a fourth pdb file and calcuating the d.m. to see what
 happens.  What I'm trying to do is compare the dipole moment of a group
 of overlayed structures.  I'm not sure what's going on!
         In addition, I have a small peptide for which I calculated and
 displayed a dipole moment.  I then mutated all of the positively charged
 residues on one face of the peptide (3 in all) to glutamate residues to
 create a mutant peptide, and calculated the dipole for this molecule
 (rereading the full.crg file).  It superimposed PERFECTLY with the
 dipole of the unmutated molecule.  Intuitively, this seemed odd.  Am I
 doing something wrong?
 	Can someone suggest another program that calculates and displays dipole
 moments of peptides and proteins?
 Cheers
 Michael
 --
 Michael Dooley PhD
 Centre for Drug Design and Development
 The University of Queensland
 Brisbane Qld 4072 Australia
 m.dooley # - at - # mailbox.uq.edu.au