“…Here, 29 indices were calculated, comprising: 1–8) Eight indices associated with the dihedral angles, phi and psi, of the protein’s backbone (wPsiH, wPsiS, wPsiI, wPhiH, wPhiS, wPhiI, Phi, Psi); 9–10) The accessible surface area (A) and the superficiality index (wSp); 11) The buried non-polar area (ΔAnp); 12) A measure of the folding degree (lnFD) introduced in our previous report [41]; 13) The squared radius of the protein (wR2); 14–20) Seven contact-based indices (wNc, wFLC, wNLC, wCO, wLCO, wRWCO, wCTP), each one weighted with seven of the above mentioned amino acid properties (HP, ECI, IP, Z1, Z2, Z3, ISA), in order to distinguish contacts involving different residues; 21–29) Nine thermodynamic indices (Gw(F), Gs(F), W(F), ΔGs, HBd, ΔGel, ΔGw, ΔGLJ, ΔGtor) associated with the number of hydrogen bonds in the backbone of the protein and several empirical approaches capturing folding free energy contributions [42, 43] referring to Lenard-Jones and electrostatic interactions, torsion potential, superficial free energy, hydrophobic effect, etc. A summary of all the structure-based indices is presented in the Additional file 2: Tables SI-3 and SI-4.…”