title: Nearest neighbor thermodynamic parameters for internal G.A mismatches in DNA.
abstract: Thermodynamics of 22 oligonucleotides with internal single G.A mismatches dissolved in 1 M NaCl were determined from absorbance versus temperature melting curves. These data, combined with five literature sequences, were used to derive nearest-neighbor thermodynamic parameters for seven linearly independent trimer sequences with internal G.A mismatches and Watson-Crick flanking base pairs. The G.A mismatch parameters predict DeltaG degrees 37, DeltaH degrees, DeltaS degrees, and TM with average deviations of 4.4%, 7.4%, 8.0%, and 1.5 degrees C, respectively. The nearest-neighbor parameters show that G.A mismatch stability is strongly context dependent, and DeltaG degrees 37 ranges from +1.16 kcal/mol for TGA/AAT to -0.78 kcal/mol for GGC/CAG. In addition, one-dimensional 1H NMR spectra show that the G.A pairing geometry is pH and context dependent.
authors.affiliation: Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
authors.forename: H T
authors.initials: HT
authors.lastname: Allawi
authors.forename: J
authors.initials: J
authors.lastname: SantaLucia
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D004247:DNA / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D004261:DNA Replication; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012313:RNA / Q000737:chemistry; D012044:Regression Analysis; D013816:Thermodynamics
chemical_list: D009838:Oligodeoxyribonucleotides; D012313:RNA; D004247:DNA