Molecular Pharmacology, Vol 13, 374-377, Copyright © 1977 by the American Society for Pharmacology and Experimental Therapeutics

Polyribonucleotide Inhibition of Murine Leukemia Virus Replication: Effect of Strandedness

¹ Department of Medical Viral Oncology, Roswell Park Memorial Institute, and Graduate Faculty in Microbiology, State University of New York, Roswell Park Division, Buffalo, New York 14263

We have previously reported on the structure-activity relationships of polyribonucleotides as inhibitors of murine leukemia virus replication in cultured cells. These studies raised the possibility that the active form of otherwise single-stranded polyribonucleotides may be a multistranded structure. We have now compared the inhibitory potencies of double- and triple-stranded complexes of poly(adenylic acid) and poly(uridylic acid) with those of single-stranded poly(adenylic acid) and poly(uridylic acid). We find that poly(adenylic acid) · poly(uridylic acid) and poly(adenylic acid). 2 poly(uridylic acid) are considerably less potent than uncomplexed poly(adenylic acid) and poly(uridylic acid). These results suggest that the inhibitory potential of polyribonucleotides does not reside in a multistranded structure but in a single-stranded molecule. These observations are consistent with the notion that the inhibition of RNA tumor virus replication by single-stranded polyribonucleotides is more likely to be due to their effect on reverse transcription than on interferon induction.