Nucleic Acids Research, 2001, Vol. 29, No. 11 2370-2376
© 2001 Oxford University Press
Solid-phase synthesis of oligopurine deoxynucleic guanidine (DNG) and analysis of binding with DNA oligomers
Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA
The first stepwise solid-phase synthesis of deoxynucleic guanidine (DNG), a positively charged DNA analog, using controlled pore glass as the solid support is reported. For the first time, purine bases have been incorporated into the DNG oligomer and DNG has been synthesized using a solid-phase method, proceeding in the 3'
5' direction, that is compatible with the cleavage conditions used in the solid-phase synthesis of DNA. A DNG sequence containing a pentameric tract of adenosine nucleosides has been synthesized and the thermal denaturation temperature of its complexes with complementary thymidyl DNA oligomers was 79°C. Binding of thymidyl DNA oligomers to adenyl DNG oligomers is 2:1, as seen in thymidyl and adenyl DNA triplexes. No binding of adenyl DNG with octameric cytidyl DNA was observed, indicating that the positive charge does not overcome base pairing fidelity.
* To whom correspondence should be addressed. Tel: +1 805 893 2044; Fax: +1 805 893 2229; Email: tcbruice{at}bioorganic.ucsb.edu Present address: Barry A. Linkletter, Department of Chemistry, University of Prince Edward Island, 550 University Avenue, Prince Edward Island C1A 4P3, Canada