(C) M and Z α1-antitrypsin were subjected to equilibrium unfolding into different concentrations of guanidine hydrochloride (gdnhcl) in the presence and absence of GSK716, with bis-ANS dye added to report the presence of the unfolded intermediate. The normalised fluorescence intensity data were fitted with an equation describing a three-state unfolding curve. Values shown are the mean of three independent experiments and the error bars represent ±SEM. 