1. Associated Unit CSIC, IN2UB, Department of Physical Chemistry, Faculty of Pharmacy, University of Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain, Department of Peptide & Protein Chemistry, IIQAB-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain, and Department of Physical Chemistry, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain