Introduction of cationic charge into DNA near the major groove edge of a guanine x cytosine base pair: characterization of oligodeoxynucleotides substituted with 7-aminomethyl-7-deaza-2'-deoxyguanosine.
The replacement of the 7-N atom on guanine (G) with a C-H to give 7-deazaguanine (c(7)G) alters the electronic properties of the heterocyclic base and eliminates a potential major groove cation binding site, which affects the organization of salts and water in the major groove. This has a destabilizing effect on DNA. We report herein the characterization of DNA oligomers containing 7-(aminomethyl)-7-deazaguanine (1) residues using a variety of spectroscopic and thermodynamic approaches. 1 is an intramolecular model for the major groove binding of cations and basic amino acid residues to G. In contrast to c(7)G, the tethering of a cation in the major groove using 1 affords DNA that is as, or more, stable than the corresponding unmodified DNA. The stabilization is associated with the folding enthalpy and hydration.
Ganguly
Manjori
M
University of Pittsburgh, Department of Pharmaceutical Sciences, 3501 Terrace Street, Pittsburgh, Pennsylvania 15261, USA.
Wang
Ruo-Wen
RW
Marky
Luis A
LA
Gold
Barry
B
D020029:Base Pairing; D001483:Base Sequence; D003596:Cytosine; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D003849:Deoxyguanosine / Q000737:chemistry*; D006147:Guanine; D009704:Nucleoside Q / Q000031:analogs & derivatives* / Q000737:chemistry; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000235:genetics; D013696:Temperature; D013816:Thermodynamics
C545059:7-aminomethyl-7-deaza-2'-deoxyguanosine; D009838:Oligodeoxyribonucleotides; D009704:Nucleoside Q; D006147:Guanine; D003596:Cytosine; D004247:DNA; D003849:Deoxyguanosine