Simple method for determining nucleobase pK(a) values by indirect labeling and demonstration of a pK(a) of neutrality in dsDNA.
Phosphorothioates were substituted into double-stranded DNA to study protonated Class I A+.C basepairs by 31P NMR. The method was effective in reporting the A+.C pKa. pKa values near 7.0 were found with optimal nearest-neighbor partners. Such pKa values could expand the catalytic repertoire of nucleic acids.
Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA.
Ellen M
EM
Moody
Trevor S
TS
Brown
Philip C
PC
Bevilacqua
D000225:Adenine / Q000737:chemistry; D020029:Base Pairing; D003596:Cytosine / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D018076:DNA, Complementary / Q000737:chemistry; D006147:Guanine / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry; D013873:Thionucleotides / Q000737:chemistry; D013941:Thymine / Q000737:chemistry
D018076:DNA, Complementary; D009841:Oligonucleotides; D013873:Thionucleotides; D006147:Guanine; D003596:Cytosine; D004247:DNA; D000225:Adenine; D013941:Thymine