Hi All,

  I have a Peptide with 12 aminoacid residues and a Ca+2 ion is also in it. Now i would like to calculate the following

1) Binding constant between the peptide and Ca+2 ion.

2) Enthalpies of binding.

3) Desolvation energies upon binding.

I applied CHARMm forcefields and minmized the structure the i have grouped the Peptide with Ca +2 as one group(Calcium_pep) and solvated it. Next i used QM/MM minimization tool for (Calcium_pep) the grouped one and the rest water particles with MM.

Is the above mentioned step accceptable or not?

If not can any one suggest me...

Thanks & Regards

TatiReddy