We describe the results of a QM/MM study starting with input structures, 1-23, in the mono, di-, tri-and quadprotonated states at pH 7. This QM/MM study is conducted with two QM regions consisting of 8 residues and 13 residues. Thus far, no QM/MM study of VCPO with 13 residues in the QM region has been reported. This study provides structural information about VCPO as well as the stability of the tri and quadprotonated states. It also provides the relative energies of the protonation states. All of this information combined together allows us to indicate what is likely to be the resting state of VCPO.