Higher affinity quadruply hydrogen-bonded complexation with 7-deazaguanine urea.
[structure: see text] UG forms a highly stable quadruply hydrogen-bonded heterocomplex with DAN, but the fidelity of the complex is lowered somewhat by the Hoogsteen-side oligomerization of UG (K(assoc) approximately 230 M(-)(1), CDCl(3)). DeUG was prepared as a more robust analogue of UG lacking the Hoogsteen nitrogen atom. Remarkably, the deaza analogue, DeUG, forms a much more stable complex with DAN (>10-fold higher K(assoc) for DeUG.DAN vs UG.DAN) but also dimerizes more strongly (K(dim) = 880 +/- 40 M(-)(1), CDCl(3)) by adopting a conformation preorganized for both binding and dimerization.
Ong
Hugo C
HC
Department of Chemistry, 600 South Mathews Avenue, University of Illinois, Urbana, Illinios 61801, USA.
Zimmerman
Steven C
SC
D006147:Guanine / Q000031:analogs & derivatives* / Q000737:chemistry; D006860:Hydrogen Bonding; D007700:Kinetics; D015394:Molecular Structure; D010619:Phenazines / Q000737:chemistry; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry*
D010619:Phenazines; C516001:ureido-7-deazaguanine; C051441:2,7-diamino-3,8-dimethylphenazine; D006147:Guanine; D014508:Urea; C010567:3-deazaguanine