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 cyt ochrome c in sodium bis(2-ethylhexyl) sulfosuccinate/water/isooctane r everse micelles induces a percolation phenomenon in dilute micellar so lution compared to empty micelles. This has been attributed to an incr ease in the interaction potential between droplets. To confirm this hy pothesis, structural studies of microemulsions filled by various cytoc hrome c differing by their net charge (+8, -3 and -12) have been perfo rmed by SAXS. The intermicellar interactions are analyzed with the adh esive hard-sphere model. It is shown that electrostatic interactions b etween the interfacial wall and the protein play an important role on the intermicellar interactions and on the percolation onset. This beha vior has been confirmed by the change in the critical temperature for empty micelles and micelles filled by various cytochrome c derivatives .