1. Department of Structural and Functional Biology, University of Naples Federico II, Napoli, Italy.
2. CNR, Institute of Protein Biochemistry, Napoli, Italy.
3. Stazione Zoologica “Anton Dohrn,” Department of Cellular and Developmental Biology, Napoli, Italy.
4. Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.