(Research School of Chemistry, The Australian National University, Canberra, ACT, Australia) Summary Sulphide, sulphoxide, and sulphone ligands CYTOCHROME C, an electron transfer agent in the respiratory were covalently attached to tetraphenylporphyrins and chain, consists of an iron protoporphyrin IX unit co- were found to bind to different extents to the iron(I1) ordinated to imidazole (His 18) and sulphide (Met 80) derivatives.
