Thermodynamics of internal C.T mismatches in DNA.
Thermodynamics of 23 oligonucleotides with internal single C.T mismatches were obtained by measuring UV absorbance as a function of temperature. Results from these 23 duplexes were combined with three measurements from the literature to derive nearest-neighbor thermodynamic parameters for seven linearly independent trimer sequences with internal C.T mismatches. The data show that the nearest-neighbor model is adequate for predicting thermodynamics of oligonucleotides with internal C.T with average deviations for Delta G degrees37, Delta H degrees, Delta S degrees and T m of 6.4%, 9.9%, 10.6%, and 1.9 degreesC respectively. C.T mismatches destabilize the duplex in all sequence contexts. The thermodynamic contribution of C. T mismatches to duplex stability varies weakly depending on the orientation of the mismatch and its context and ranges from +1.02 kcal/mol for GCG/CTC and CCG/GTC to +1.95 kcal/mol for TCC/ATG.
Allawi
H T
HT
Department of Chemistry, Wayne State University, Detroit, MI 48202, USA.
SantaLucia
J
J
D003562:Cytidine; D004247:DNA / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D019906:Nuclear Magnetic Resonance, Biomolecular; D009692:Nucleic Acid Heteroduplexes; D013816:Thermodynamics; D013936:Thymidine
D009692:Nucleic Acid Heteroduplexes; D003562:Cytidine; D004247:DNA; D013936:Thymidine