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Calorimetric determination of base‐stacking enthalpies in double‐helical DNA molecules
Author(s) -
Marky Luis A.,
Breslauer Kenneth J.
Publication year - 1982
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360211107
Subject(s) - chemistry , stacking , enthalpy , differential scanning calorimetry , calorimetry , crystallography , molecule , base pair , base (topology) , transition temperature , dna , thermodynamics , organic chemistry , biochemistry , mathematical analysis , physics , mathematics , superconductivity , quantum mechanics
Differential scanning calorimetry was used to directly determine the transition enthalpies accompanying the duplex‐to‐single‐strand transition of poly[d(AT)], poly(dA)·poly(dT), poly[d(AC)]·poly[d(TG)], and d(GCGCGC). The calorimetric data allow us to define the following average base‐stacking enthalpies:Interaction Δ H (kcal/stack)AC/TG, TG/AC 5.6 AT/TA, TA/AT 7.1 AA/TT 8.6 GC/CG, CG/GC 11.9Comparison with published data on the corresponding RNA interactions reveals remarkably good agreement. By assuming transition enthalpies to result from the pairwise disruption of nearest‐neighbor stacking interactions, we used the enthalpy data listed above to predict the transition enthalpies for three oligomeric DNA duplexes. Excellent agreement was found between the predicted and the calorimetrically determined values.