Abstract
The selfassociation of N6,N9-dimethyladenine and N6-dimethyl-N9-ethyladenine has been studied by means of NMR technique. The thermodynamic quantities have been calculated using an isodesmic NMR model with three NMR parameters (the monomer shift δM and two complex shifts δ 2 and δ 3).
The dependence of the thermodynamic quantities on the NMR parameters is discussed. Special attention is given to the determination of δ M and its temperature dependence.
Calculations with δ 3=2·δ 2 and δ M taken independently of temperature result in an average entropy δ S =−17.9±1.8 e.u. for N6,N9-dimethyladenine and δ S =−16.7±1.7 e.u. for N6-dimethyl-N9-ethyladenine and in an average enthalpy δH=−7.2±0.6 kcal· mol−1 for both substances investigated.
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Antonovsky, V. L., Gukovskaja, A. S., Nekrasova, G. V., Sukhorukov, B. J., Tchervin, I. I.: Studies of intermolecular interactions of nucleic acid bases in aqueous solutions by the proton magnetic resonance method. Selfassociation of 6,9-dimethyladenine and its pyrazole analogue and their association with methyl-substituted cytosine and uracil. Biochim. biophys. Acta (Amst.) 331, 9–20 (1973)
Bretz, R., Lustig, A., Schwarz, G.: Selfassociation studies of two adenine derivatives by equilibrium ultracentrifugation. Biophys. Chem. 1, 237–241 (1974)
Deranleau, D. A.: Theory of the measurement of weak molecular complexes. I. General considerations. J. Amer. chem. Soc. 91, 4044–49 (1969)
Dimicoli, J. L., Helene, C.: Complex formation between purine and indole derivatives in aqueous solutions. Proton magnetic resonance studies. J. Amer. chem. Soc. 95, 1036–44 (1973)
Hruska, F. E., Bell, C. L., Victor, T. A., Danyluk, S. S.: Medium effects on the nuclear magnetic resonance spectra of purines. Biochemistry 7, 3721–27 (1968)
Lawaczeck, R.: Stacking Assoziate der decarboxylierten aromatischen AminosÄuren mit Monound Oligonucleotiden. Ph.D. thesis, Technische UniversitÄt Braunschweig 1972
Lüdemann, H. D., von Goldammer, E.: The association between purine nucleosides and benzene in aqueous solution, studied by proton magnetic resonance and nuclear Overhauser enhancements. Z. Naturforsch. 28c, 361–369 (1973)
Marenchic, M. G., Sturtevant, J. M.: Calorimetric investigation of the association of Various purine bases in aqueous media. J. physic. Chem. 77, 544–548 (1973)
Pörschke, D., Eggers, F.: Thermodynamics and kinetics of base stacking interactions. Europ. J. Bioohem. 26, 490–498 (1972)
Ts'o, P. O. P.: Fine structure of proteins and nucleic acids (eds. G. D. Fasman, S. N. Timasheff). New York: Marcel Dekker 1970
Van Geet, A. L.: Calibration of the methanol and glycol nuclear magnetic resonance thermometers with a static thermistor probe. Anal. Chem. 40, 2227–29 (1963)
Van Geet, A. L.: Calibration of methanol nuclear magnetic resonance thermometer at low temperature. Anal. Chem. 42, 679–680 (1970)
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Dedicated to Professor Dr. A. Schraub on the occasion of his 65th birthday.
Part of the Ph.D. Theses of W. Schimmack and H. Sapper.
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Schimmack, W., Sapper, H. & Lohmann, W. Stacking Interactions of nucleobases: NMR-Investigations I. Selfassociation of N6,N9-Dimethyladenine and N6-Dimethyl-N9-Ethyladenine. Biophys. Struct. Mechanism 1, 113–120 (1975). https://doi.org/10.1007/BF00539773
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DOI: https://doi.org/10.1007/BF00539773