The met axial ligand determines the redox potential in Cu(A) sites.

@article{Ledesma2007TheMA,
  title={The met axial ligand determines the redox potential in Cu(A) sites.},
  author={Gabriela N. Ledesma and Daniel H Murgida and Hoang Khoa Ly and Hainer Wackerbarth and Jens Ulstrup and Antonio Jos{\'e} Costa-Filho and Alejandro J. Vila},
  journal={Journal of the American Chemical Society},
  year={2007},
  volume={129 39},
  pages={11884-5}
}