Fig. 3: Comparison of the ΔG of each step of the reaction catalyzed by Cu sites with different structures.

a Cu²⁺ coordinates with four imidazolyls. b Cu²⁺ coordinates with one amino and three imidazolyls. c Cu²⁺ coordinates with one carboxyl and three imidazolyls. d Cu²⁺ coordinates with one amino, one carboxyl and two imidazolyls.