ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Phosphate-methylated (P.M.) DNA possesses a very high affinity for complementary natural DNA, as a result of the absence of interstrand electrostatic repulsions. In this study, a model system phosphate-methylated d[Cn] with natural d(Gk) (n 〈 k)is chosen for an investigation of the thermodynamic properties that determine duplex stability. The enthalpy change of a melting transition is shown to be considerably larger than is observed for corresponding natural DNA duplexes. It is found that ΔH0n of GG/CC nearest neighbor pairwise interaction equals -15.6 kcal/mol, compared to -11.0 kcal/mol for the natural analog. The entropy change is strongly dependent on the length of the natural DNA strand and the number of phosphate-methylated DNA oligomers hybridized. The results are explained by means of a model in which a cooperative effect for subsequent hybridizations of phosphate-methylated DNA oligomers is assumed, thus giving additional stability.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360300513
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