... thesame time, distinct absorption bands of oxyhemeappeared at 540 and 579 nm. Then, a broad bandappeared at around 660 nm, and was maximal 9–12 minafter initiation of the reaction. The spectral ... GC, Katakura K, Tomita T, Zhang X, Sun D,Sato M, Sasahara M, Kayama T, Ikeda-Saito M &Yoshida T (2000) Histidine 20, the crucial proximalaxial heme ligand of bacterial heme oxygenase Hmu ... bindingAzide, like imidazole, is a ligand with both r-donorand p-donor characteristics, but is a relatively stron-ger p-donor for stabilization of the higher oxidationstates of metal ions. In agreement...