Abstract
High resolution proton magnetic resonance measurements provide evidence for the formation of hydrogen-bonded complexes between 9-ethyladenine and p-cresol used as a model of tyrosine side chain in CDCl3. We have calculated the sum of the association constants corresponding to the three existing 1:1 complexes: K=6.3+/-0.15. By methylation of the amino group of adenine, we were able to calculate the ratio of the two strongest equilibrium constants K7/K1=1.6+/-0.3. Theoretical computations by the complete neglect of differential overlap (CNDO/2) method indicate that several hydrogen-bonded planar complexes can form between 9-methyladenine and phenol. The computed energy of the complexes with 6-dimethylamino adenine removes some ambiguity concerning the computed ratio of the association constants. Comparison of the calculated energies with free energies experimentally determined in organic solvent shows that despite the competition with CDCl3, which associates with both solute molecules, the preferential order of association is conserved. The small variations of charge density of adenine carbon atoms when complexed with phenol are in agreement with very small chemical shifts observed by 13C-nuclear magnetic resonance.
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- Blow D. M., Steitz T. A. X-ray diffraction studies of enzymes. Annu Rev Biochem. 1970;39:63–100. doi: 10.1146/annurev.bi.39.070170.000431. [DOI] [PubMed] [Google Scholar]
- Brun F., Toulmé J. J., Hélène C. Interactions of aromatic residues of proteins with nucleic acids. Fluorescence studies of the binding of oligopeptides containing tryptophan and tyrosine residues to polynucleotides. Biochemistry. 1975 Feb 11;14(3):558–563. doi: 10.1021/bi00674a015. [DOI] [PubMed] [Google Scholar]
- Dimicoli J. L., Hélène C. Interactions of aromatic residues of proteins with nucleic acid. II. Proton magnetic resonance studies of the binding of tyramine and tyrosine-containing peptides to poly(adenylic acid) and deoxyribonucleic acid. Biochemistry. 1974 Feb 12;13(4):724–730. doi: 10.1021/bi00701a014. [DOI] [PubMed] [Google Scholar]
- Engel J. D., von Hippel P. H. Effects of methylation on the stability of nucleic acid conformations: studies at the monomer level. Biochemistry. 1974 Sep 24;13(20):4143–4158. doi: 10.1021/bi00717a013. [DOI] [PubMed] [Google Scholar]
- Gabbay E. J., Adawadkar P. D., Kapicak L., Pearce S., Wilson W. D. The interaction specificity of peptides with DNA. Evidence for peptide beta-sheet-DNA binding. Biochemistry. 1976 Jan 13;15(1):152–157. doi: 10.1021/bi00646a023. [DOI] [PubMed] [Google Scholar]
- Gabbay E. J., Adawadkar P. D., Wilson W. D. Stereospecific binding of diastereomeric peptides to salmon sperm DNA. Biochemistry. 1976 Jan 13;15(1):146–151. doi: 10.1021/bi00646a022. [DOI] [PubMed] [Google Scholar]
- Jones A. J., Grant D. M., Winkley M. W., Robins R. K. Carbon-13 magnetic resonance. XVII. Pyrimidine and purine nucleosides. J Am Chem Soc. 1970 Jul 1;92(13):4079–4087. doi: 10.1021/ja00716a042. [DOI] [PubMed] [Google Scholar]
- Olins D. E., Olins A. L., Von Hippel P. H. Model nucleoprotein complexes: studies on the interaction of cationic homopolypeptides with DNA. J Mol Biol. 1967 Mar 14;24(2):157–176. doi: 10.1016/0022-2836(67)90324-5. [DOI] [PubMed] [Google Scholar]
- Sellini H., Maurizot J. C., Dimicoli J. L., Helene C. Hydrogen bonding of amino acid side chains to nucleic acid bases. FEBS Lett. 1973 Mar 1;30(2):219–224. doi: 10.1016/0014-5793(73)80655-6. [DOI] [PubMed] [Google Scholar]
- Shapiro J. T., Leng M., Felsenfeld G. Deoxyribonucleic acid-polylysine complexes. Structure and nucleotide specificity. Biochemistry. 1969 Aug;8(8):3219–3232. doi: 10.1021/bi00836a014. [DOI] [PubMed] [Google Scholar]
- Toulmé J. J., Charlier M., Héléne C. Specific recognition of single-stranded regions in ultraviolet-irradiated and heat-denatured DNA by tryptophan-containing peptides. Proc Natl Acad Sci U S A. 1974 Aug;71(8):3185–3188. doi: 10.1073/pnas.71.8.3185. [DOI] [PMC free article] [PubMed] [Google Scholar]