1. Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Naples, Italy
2. Department of Biology, University of Naples Federico II, Via Cinthia 4, 80126, Naples, Italy
3. Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
4. Magnetic Resonance Center (CERM), University of Florence, and Consorzio Interuniversitario Risonanze Magnetiche di Metallo Proteine (CIRMMP), Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy
5. Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy
6. Division of Infectious Diseases, Veterans Affairs Medical Center, Department of Medicine, University of California, San Francisco, California 94121, USA
7. Northern California Institute for Research and Education, San Francisco, California 94121, USA