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. Fig, Temperature dependence of ?H Tm for wt and ProE3Gly Tf-trHbO (A) and wt and GlyE3Pro Mt-trHbO (B) trHbs. The thermodynamic parameters ?H Tm and T m , obtained from the fitting procedure of the melting profiles of Fig. 1S are shown as a function of GdmCl concentration (0.5, 1, 1.5 and 2 M, respectively) The slopes yielded values of ?C p (kcal · mol ?1 · K ?1 ) of 1.56 ± 0.07 for wt Tf-trHbO (?), 1.22 ± 0, 07 for ProE3Gly TftrHbO (?) and 1.21 ± 0.07 for wt Mt-trHbO (?), 1.28 ± 0.06 for GlyE3Pro Mt-trHbO (?), respectively. Preferred magnification factor: single column

. Fig, The salt-bridge interactions between CD loop and B ?-helix at the protein surface on Tf-trHbO is shown. It can be assumed that GdmCl molecules are able to disrupt this network interactions due to fact that they have complete access from solvent environment

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