Penetratin-induced aggregation and subsequent dissociation of negatively charge phospholipid vesicles

The interaction of the cellular delivery vector penetratin with a model sys tem consisting of negatively charged phospholipid vesicles has been studied . Above a certain peptide to lipid molar ratio, the cationic oligopeptide i nduces vesicle aggregation. Interestingly, the aggregation is followed by s pontaneous disaggregation, which may be related to membrane translocation o f the peptide. Circular dichroism (CD) measurements indicate a conformation al transition, from alpha -helix to antiparallel beta -pleated sheet, which is simultaneous with the aggregation process. The potential influence of s pectroscopic artifacts on CD data due to the drastically increased turbidit y during aggregation is discussed. (C) 2001 Published by Elsevier Science B .V. on behalf of the Federation of European Biochemical Societies.