Thermodynamic parameters for peptide binding to GST-Als5 and GST-Als5-SS.

Peptides ligands used are from a previously identified ligand library [29].The dissociation constants (Kd) for peptide binding to GST-Als5 and GST-Als5-SS were obtained from the binding plots shown in Figure S8 (B, D, F & H) and Figure S9 (B, D, F & H) respectively. The standard state free energy (ΔGo) values at different temperatures were calculated using the equation ΔGo = -RTln Ka (where Ka refers to the association constant for the protein-peptide interaction). Standard state enthalpy (ΔHo) and entropy (ΔSo) values were obtained from the van’t Hoff plots for the protein-peptide interactions (Figure 8A & 8B). N.B. implies no binding observed.*The secondary structure of the Als5 and Als5-SS were mildly perturbed at 52oC as compared to that at the lower temperatures from CD spectral studies (data not shown).