Table 2. pK_a Values for the Four Histidine Residues in the OR Peptide, Calculated for the Final MD Models from Simulations with a Single Bound Metal Ion and either Protonated (Figures 6A and 7A) or Neutral Histidine Residues (Figures 6B and 7B), and with either the PropKa 2.0 or DelPhiPKa 2.3 Protocol.

	final MD models from simulations with neutral histidine residues		final MD models from simulations with protonated histidine residues
	Cu(II)	Zn(II)	Cu(II)	Zn(II)
PropKa 2.0
His61	5.87	6.88	6.50	6.43
His69	6.41	6.01	6.50	6.43
His77	6.20	6.11	6.43	6.29
His85	6.48	7.15	6.47	6.50
DelPhiPKa 2.3
His61	5.64	5.88	6.43	6.43
His69	6.11	6.06	6.45	6.43
His77	6.10	6.12	6.49	6.29
His85	6.16	6.18	6.46	6.50