1 Department of Physiological Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy; National Institute of Biostructures and Biosystems, Viale Medaglie d'Oro, 305 Roma, Italy.
2 Department of Biological Chemistry, Medicinal Chemistry and Molecular Biology, University of Catania, Viale A. Doria 6, 95125 Catania, Italy.
3 Institute of Neurological Sciences, Section of Catania, National Research Council, Viale Regina Margherita 6, 95123 Catania, Italy.
4 AIDS National Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy.
5 Department of Physiological Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy; National Institute of Biostructures and Biosystems, Viale Medaglie d'Oro, 305 Roma, Italy. Electronic address: [email protected].