Abstract: | We have measured the circular dichroism (CD) and absorption properties of polyr(G-U)] and poly d(G-T)] over a wide range of Na+ concentrations and temperatures. We find evidence for self-complexed forms of these polymers at lower temperatures and/or higher Na+ concentrations than generally needed for double-strand formation in other DNA and RNA polymers. These self-complexes could be composed of double-stranded regions with weak G·U or G·T base pairs. |