Murine recombinant prion protein induces ordered aggregation of linear nucleic acids to condensed globular structures

Interaction between nucleic acid and recombinant murine prion protein, MoPr PC resulted in a time-dependent change in the nucleic acid morphology revea led by electron microscopy. After the addition of the protein to DNA, assoc iation of small number of nucleic acid molecules (nucleo-protein complex) w as followed by aggregation of large number of them still retaining their in itial linear morphology. With increase in the incubation time, ordered aggr egation resulted in small condensed spherical globules. Subsequently, the f ormation of large condensed particles took place either by fusion of the al ready formed small globules or by accumulation of more nucleic acid molecul es on them. The condensed nucleic acid structures observed here were differ ent from other known morphologically altered nucleic acid structures induce d by different cellular proteins. The condensed nucleic acid structures dis sociated spontaneously. The formation of the prion protein-induced condense d nucleic acid structures resembled the human immunodeficiency virus 1 nucl eocapsid protein NCp7-induced condensed ordered aggregates of nucleic acids . In the latter system, both the processes of condensation and dissociation of the nucleoprotein complex are believed to be responsible for the functi onal properties of the HIV-1 virus. Demonstration of functional activity of the prion protein-nucleic acid complex would be relevant for a role of nuc leic acid in prion diseases.