• Publications
  • Influence
Endogenous 5-methylcytosine protects neighboring guanines from N7 and O6-methylation and O6-pyridyloxobutylation by the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone.
All CG dinucleotides along exons 5-8 of the p53 tumor suppressor gene contain endogenous 5-methylcytosine (MeC). These same sites (e.g., codons 157, 158, 245, 248, and 273) are mutational hot spotsExpand
  • 35
  • 3
Thermodynamic versus kinetic products of DNA alkylation as modeled by reaction of deoxyadenosine.
Alkylating agents that react through highly electrophilic quinone methide intermediates often express a specificity for the weakly nucleophilic exocyclic amines of deoxyguanosine (dG N(2)) andExpand
  • 58
  • 2
Formation of benzo[a]pyrene diol epoxide-DNA adducts at specific guanines within K-ras and p53 gene sequences: stable isotope-labeling mass spectrometry approach.
The mutagenicity of a prominent tobacco carcinogen, benzo[a]pyrene (B[a]P), is believed to result from chemical reactions between its diol epoxide metabolite,Expand
  • 76
  • 1
Peroxynitrite-induced reactions of synthetic oligo 2'-deoxynucleotides and DNA containing guanine: formation and stability of a 5-guanidino-4-nitroimidazole lesion.
Peroxynitrite is a strong oxidizing agent that is formed in the reaction of nitric oxide and superoxide anion. It is capable of oxidizing and nitrating a variety of biological targets including DNA,Expand
  • 40
  • 1
K-ras gene sequence effects on the formation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-DNA adducts.
The tobacco specific pulmonary carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is metabolically activated to electrophilic species that form methyl and pyridyloxobutyl adducts withExpand
  • 40
  • 1
Aminoglycoside complexation with a DNA.RNA hybrid duplex: the thermodynamics of recognition and inhibition of RNA processing enzymes.
Spectroscopic and calorimetric techniques were employed to characterize and contrast the binding of the aminoglycoside paromomycin to three octamer nucleic acid duplexes of identical sequence butExpand
  • 23
  • 1
Formation of 13C-, 15N-, and 18O-labeled guanidinohydantoin from guanosine oxidation with singlet oxygen. Implications for structure and mechanism.
Guanosine labeled with 15N at N1, amino, and N7 and 13C at either C2 or C8 was oxidized by Rose Bengal photosensitization (singlet oxygen) in buffered aqueous solution. At pH > 7,Expand
  • 115
Use of a 13C Atom To Differentiate Two 15N-Labeled Nucleosides. Syntheses of [15NH2]-Adenosine, [1,NH2-15N2]- and [2-13C-1,NH2-15N2]-Guanosine, and [1,7,NH2-15N3]- and
We report the first examples of the specifically 15N and 13C multilabeled nucleosides:  [1,NH2-15N2]-and [2-13C-1,NH2-15N2-]-guanosine; [1,7,NH2-15N3]- and [2-13C-1,7,NH2-15N3]-2‘-deoxyguanosine. InExpand
  • 33
A double chain reversal loop and two diagonal loops define the architecture of a unimolecular DNA quadruplex containing a pair of stacked G(syn)-G(syn)-G(anti)-G(anti) tetrads flanked by a G-(T-T)
The architecture of G-G-G-G tetrad-aligned DNA quadruplexes in monovalent cation solution is dependent on the directionality of the four strands, which in turn are defined by loop connectivities andExpand
  • 52
Use of 13C as an indirect tag in 15N specifically labeled nucleosides. Syntheses of [8-13C-1,7,NH2-15N3]adenosine, -guanosine, and their deoxy analogues.
We have previously reported the use of a 13C tag at the C2 of 15N-multilabeled purine nucleosides to distinguish the adjacent-labeled 15N atoms from those in an untagged nucleoside. We now introduceExpand
  • 25