Table 2.

Experimental and calculated Cu–S(Met) bond strengths in BC, delocalized, and localized Cu_A sites

Model*	Blue copper	Deloclized CuA (CuO–CuM)	Localized CuA (ZnO–CuM)
Exp†	4.6	n.d.	n.d.
Reduced‡	1.8	1.1	4.6
Oxidized§	7.5	5.2	16.8
ΔΔE(ox-red)	5.7	4.1	12.2

^*Constrained Met residue replaced by dimethyl thioether.

^†kcal/mol.

^‡Energies are relative to a 10 Å Cu_M–S(thioether) distance. For Cu⁺ BC d_{Cu–S(thioether)–red .}is fixed at d_{Cu–S(thioether)–ox}.

^§Energies are obtained the same way as Cu⁺ BC.