Twenty-five years of cytochrome oxidase research in Rome with Maurizio Brunori

Cytochrome c oxidase has been for a long time one of the central topics studied in Rome by Maurizio Brunori. The authors of this paper have had the unique opportunity of collaborating with him and his friends worldwide for many years. Among the very large number of papers on this enzyme produced by Maurizio Brunori, just a few have been selected here which are particularly representative for the three of us. Topics deal mostly with the interplay between the electrochemical potential gradient in its components and the electron transfer and the proton translocation reactions of this fascinating enzyme.