title: Synthesis of a thymidyl pentamer of deoxyribonucleic guanidine and binding studies with DNA homopolynucleotides.
abstract: Replacement of the phosphodiester linkages of the polyanion DNA with guanidine linkers provides the polycation deoxynucleic guanidine (DNG). The synthesis of pentameric thymidyl DNA is provided. This polycationic DNG species binds with unprecedented affinity and with base-pair specificity to negatively charged poly(dA) to provide both double and triple helices. The dramatic stability of these hybrid structures is shown by their denaturation temperatures (Tm). For example, the double helix of the pentameric thymidyl DNG and poly(dA) does not dissociate in boiling water (ionic strength = 0.12), whereas the Tm for pentameric thymidyl DNA associated with poly(dA) is approximately 13 degrees C (ionic strength = 0.12). The effect of ionic strength on Tm for DNG complexes with DNA shows an opposite correlation compared with double-stranded DNA and is much more dramatic than for double-stranded DNA.
authors.affiliation: Department of Chemistry, University of California, Santa Barbara 93106, USA.
authors.forename: R O
authors.initials: RO
authors.lastname: Dempcy
authors.forename: K A
authors.initials: KA
authors.lastname: Browne
authors.forename: T C
authors.initials: TC
authors.lastname: Bruice
mesh_terms: D001482:Base Composition; D001665:Binding Sites; D004247:DNA / Q000138:chemical synthesis* / Q000737:chemistry* / Q000378:metabolism; D004355:Drug Stability; D006146:Guanidines / Q000138:chemical synthesis* / Q000737:chemistry*; D006358:Hot Temperature; D007202:Indicators and Reagents; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis* / Q000737:chemistry*; D009994:Osmolar Concentration; D013816:Thermodynamics
chemical_list: D006146:Guanidines; D007202:Indicators and Reagents; D009838:Oligodeoxyribonucleotides; C094338:pentameric thymidyl deoxynucleic guanidine; D004247:DNA