COMPLEXES OF NON-CATIONIC LIPOSOMES AND HISTONE H1 MEDIATE EFFICIENT TRANSFECTION OF DNA WITHOUT ENCAPSULATION

Transfection competent complexes were assembled using a three componen t system. The constituents of the basic system were plasmid DNA, catio nic DNA binding protein (NLS-H1) and anionic liposomes (dioleoyl phosp hatidylethanolamine (DOPE) or phosphatidylserine (PS)). In contrast to cationic liposome/DNA binary complexes, all of the DNA in these terna ry complexes was sensitive to DNase I degradation and ethidium bromide intercalation. Transmission electron microscopy revealed that these t ernary complexes formed unique structures in which the DNA was located either on the outside of individual liposomes or bridging two or more liposomes. This provides evidence that plasmid DNA encapsulation is n ot essential for transfection competency.