CHEMICALLY-MODIFIED PROTEINS SOLUBILIZED IN AOT REVERSE MICELLES - INFLUENCE OF PROTEINS CHARGES ON INTERMICELLAR INTERACTIONS

In previous papers it has been shown that solubilization of native cytochrome c in sodium bis(2-ethylhexyl) sulfosuccinate/water/isooctane reverse micelles induces a percolation phenomenon in dilute micellar solution compared to empty micelles. This has been attributed to an increase in the interaction potential between droplets. To confirm this hypothesis, structural studies of microemulsions filled by various cytochrome c differing by their net charge (+8, -3 and -12) have been performed by SAXS. The intermicellar interactions are analyzed with the adhesive hard-sphere model. It is shown that electrostatic interactions between the interfacial wall and the protein play an important role on the intermicellar interactions and on the percolation onset. This behavior has been confirmed by the change in the critical temperature for empty micelles and micelles filled by various cytochrome c derivatives.