Cytochrome c Oxidase (CcO)

							   Cytochrome c Oxidase (CcO)

• Function: ! mitochondrial O2 reduction/proton pump
              for energy storage as ATP
• Found: !     all animals, plants, aerobic yeasts,
                some bacteria
• MW: !        204,005 g
!    !
• protein: !   13 subunits, 3606 amino acids!


• active sites: !2 cytochromes (hemea, hemea3)
                 3 Cu’s (CuB + Cu2A (binuclear)
   Outer membrane                                 matrix




                               Inner membrane

Inter membrane space (IMS)




                                                   [H+]high          ADP + Pi + H+

                                                            H+     !G= +7.3 kcal/mol

                                                   [H+]low           ATP + H2O


   [H+]= small          e–

                       NAD+        e–                         intermembrane
mitochondrial
                             FAD                              space (IMS)
matrix                                       e–
                        e–
                 H+      H+        e–                      O2
                                                    e–
                                        H+
                      inner mitochondrial         H+
                      membrane
                                                         [H+]= larger
Cytochrome c Oxidase (CcO)




                    Carr, Winge, Acc. Chem. Res,
                    2003, 36, 309–316.




Cytochrome c Oxidase (CcO)




                     Carr, Winge, Acc. Chem. Res,
                     2003, 36, 309–316.
                        The binuclear CuA site of
                       Cytochrome c Oxidase (CcO)


                                                    the initial
                                                    electron
                                                    acceptor


Carr, Winge, Acc. Chem. Res,
2003, 36, 309–316.