Not sure if all the sirs will concur (and it might be a good idea to ask
madams also), but the answer is probably no. As far as protonation
state goes (guess that is what you are after, not oxidation), a better
strategy may be to look into the bond lengths between the appropriate
heavy atoms that are affected by it. Make sure that you refine without
restraints imposed on a particular bond and see if its length is closer
to the one corresponding to protonated or deprotonated state.
Cheers,
Ed.
On Mon, 2010-11-22 at 23:18 -0600, Kenneth Satyshur wrote:
> Sirs:
>
> We are attempting to refine hydrogens on a ligand (which is 100 % occupied) and
> has ~ 40 heavy atoms (CNO). The data is 1.2 A, 325 AA, 83335 data points in C2.
> We have refined aniso and with H riding along (Rf= 17, R = 15) in CCP4. Can we individually
> refine the protons on the ligand? Let them run free with the others along for the ride?
> Or will they just run away at this
> resolution? Can CCP4 even do this? Should we switch to Shelx or Phenix?
> It is important to find out what the oxidation state is for the ligand at the pH
> we crystallized the protein and complex.
>
> thanks
>
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