Different classes of copper-binding sites in proteins, classified by their spectroscopic properties as Cu(II). In type 1, or blue copper centers the copper is coordinated to at least two imidazole nitrogens from histidine and one sulfur from cysteine. They are characterized by small copper hyperfine couplings and a strong visible absorption in the Cu(II) state. In type 2, or non-blue copper sites, the copper is mainly bound to imidazole nitrogens from histidine. Type 3 copper centers comprise two spin-coupled copper ions, bound to imidazole nitrogens.
Search the Dictionary
