Abstract
The nucleoside analogs 7-(2'-deoxy-alpha-D-ribofuranosyl)hypoxanthine (alpha7H,1), 7-(2'-deoxy-beta-D-ribofuranosyl)hypoxanthine (beta7H,2) and 7-7-(2'-O-methyl-beta-D- ribofuranosyl)hypoxanthine (beta7HOMe,3) were prepared and incorporated into triplex forming oligodeoxynucleotides, designed to bind to DNA in the parallel (pyrimidine.purine-pyrimidine) motif. By DNase I footprinting techniques and UV-melting curve analysis it was found that, at pH 7. 0, the 15mer oligonucleotides d(TTTTTMeCTXTMeCTMeCTMeCT) (MeC = 5-methyl-deoxycytidine, X =beta7H,beta7HOMe) bind to a DNA target duplex forming a H.G-C base triple with equal to slightly increased (10-fold) stability compared to a control oligodeoxynucleotide in which the hypoxanthine residue is replaced by MeC. Remarkably, triple-helix formation is specific to G-C base pairs and up to 40 microM third strand concentration, no stable triplex exhibiting H.A-T, H.T-A or H.C-G base arrangements could be found (target duplex concentration approximately 0.1 nM). Multiply substituted sequences containing beta7H residues either in an isolated [d(TTTTTbeta7HTbeta7HTbeta7HTbeta7HTbeta7HT)] or in a contiguous [d(TTTbeta7Hbeta7Hbeta7Hbeta7HTTTTbeta7HTTT)] manner still form triplexes with their targets of comparable stability as the control (MeC-containing) sequences at pH 7.0 and high salt or spermine containing buffers. General considerations lead to a structural model in which the recognition of the G-C base pair by hypoxanthine takes place via only one H-bond of the N-H of hypoxanthine to N7 of guanine. This model is supported by a molecular dynamics simulation. A general comparison of the triplex forming properties of oligonucleotides containing beta7H with those containing MeC or N7-2'-deoxyguanosine (N7G) reveals that monodentate recognition in the former case can energetically compete with bidentate recognition in the latter two cases.
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Selected References
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- Arnott S., Selsing E. Structures for the polynucleotide complexes poly(dA) with poly (dT) and poly(dT) with poly(dA) with poly (dT). J Mol Biol. 1974 Sep 15;88(2):509–521. doi: 10.1016/0022-2836(74)90498-7. [DOI] [PubMed] [Google Scholar]
- Bates P. J., Laughton C. A., Jenkins T. C., Capaldi D. C., Roselt P. D., Reese C. B., Neidle S. Efficient triple helix formation by oligodeoxyribonucleotides containing alpha- or beta-2-amino-5-(2-deoxy-D-ribofuranosyl) pyridine residues. Nucleic Acids Res. 1996 Nov 1;24(21):4176–4184. doi: 10.1093/nar/24.21.4176. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Beal P. A., Dervan P. B. Second structural motif for recognition of DNA by oligonucleotide-directed triple-helix formation. Science. 1991 Mar 15;251(4999):1360–1363. doi: 10.1126/science.2003222. [DOI] [PubMed] [Google Scholar]
- Brunar H., Dervan P. B. Sequence composition effects on the stabilities of triple helix formation by oligonucleotides containing N7-deoxyguanosine. Nucleic Acids Res. 1996 Jun 1;24(11):1987–1991. doi: 10.1093/nar/24.11.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chenon M. T., Pugmire R. J., Grant D. M., Panzica R. P., Townsend L. B. Carbon-13 magnetic resonance. XXVI. A quantitative determination of the tautomeric populations of certain purines. J Am Chem Soc. 1975 Aug 6;97(16):4636–4642. doi: 10.1021/ja00849a028. [DOI] [PubMed] [Google Scholar]
- Durland R. H., Kessler D. J., Gunnell S., Duvic M., Pettitt B. M., Hogan M. E. Binding of triple helix forming oligonucleotides to sites in gene promoters. Biochemistry. 1991 Sep 24;30(38):9246–9255. doi: 10.1021/bi00102a017. [DOI] [PubMed] [Google Scholar]
- Durland R. H., Rao T. S., Bodepudi V., Seth D. M., Jayaraman K., Revankar G. R. Azole substituted oligonucleotides promote antiparallel triplex formation at non-homopurine duplex targets. Nucleic Acids Res. 1995 Feb 25;23(4):647–653. doi: 10.1093/nar/23.4.647. [DOI] [PMC free article] [PubMed] [Google Scholar]
- François J. C., Saison-Behmoaras T., Hélène C. Sequence-specific recognition of the major groove of DNA by oligodeoxynucleotides via triple helix formation. Footprinting studies. Nucleic Acids Res. 1988 Dec 23;16(24):11431–11440. doi: 10.1093/nar/16.24.11431. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Froehler B. C., Terhorst T., Shaw J. P., McCurdy S. N. Triple-helix formation and cooperative binding by oligodeoxynucleotides with a 3'-3' internucleotide junction. Biochemistry. 1992 Feb 18;31(6):1603–1609. doi: 10.1021/bi00121a004. [DOI] [PubMed] [Google Scholar]
- Griffin L. C., Dervan P. B. Recognition of thymine adenine.base pairs by guanine in a pyrimidine triple helix motif. Science. 1989 Sep 1;245(4921):967–971. doi: 10.1126/science.2549639. [DOI] [PubMed] [Google Scholar]
- Kandimalla E. R., Manning A. N., Venkataraman G., Sasisekharan V., Agrawal S. Single strand targeted triplex formation: targeting purine-pyrimidine mixed sequences using abasic linkers. Nucleic Acids Res. 1995 Nov 11;23(21):4510–4517. doi: 10.1093/nar/23.21.4510. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Montgomery J. A., Thomas H. J. Ribosyl derivatives of hypoxanthine. J Org Chem. 1969 Sep;34(9):2646–2650. doi: 10.1021/jo01261a034. [DOI] [PubMed] [Google Scholar]
- Moser H. E., Dervan P. B. Sequence-specific cleavage of double helical DNA by triple helix formation. Science. 1987 Oct 30;238(4827):645–650. doi: 10.1126/science.3118463. [DOI] [PubMed] [Google Scholar]
- Ono A., Chen C. N., Kan L. S. DNA triplex formation of oligonucleotide analogues consisting of linker groups and octamer segments that have opposite sugar-phosphate backbone polarities. Biochemistry. 1991 Oct 15;30(41):9914–9912. doi: 10.1021/bi00105a015. [DOI] [PubMed] [Google Scholar]
- Rousseau R. J., Robins R. K., Townsend L. B. Purine nucleosides. XX. The synthesis of 7-beta-D-ribofuranosylpurines from imidazole nucleoside derivatives. J Am Chem Soc. 1968 May 8;90(10):2661–2668. doi: 10.1021/ja01012a035. [DOI] [PubMed] [Google Scholar]
- Stilz H. U., Dervan P. B. Specific recognition of CG base pairs by 2-deoxynebularine within the purine.purine.pyrimidine triple-helix motif. Biochemistry. 1993 Mar 9;32(9):2177–2185. doi: 10.1021/bi00060a008. [DOI] [PubMed] [Google Scholar]
- Sun J. S., De Bizemont T., Duval-Valentin G., Montenay-Garestier T., Hélène C. Extension of the range of recognition sequences for triple helix formation by oligonucleotides containing guanines and thymines. C R Acad Sci III. 1991;313(13):585–590. [PubMed] [Google Scholar]
- Zhou B. W., Marchand C., Asseline U., Thuong N. T., Sun J. S., Garestier T., Hélène C. Recognition of alternating oligopurine/oligopyrimidine tracts of DNA by oligonucleotides with base-to-base linkages. Bioconjug Chem. 1995 Sep-Oct;6(5):516–523. doi: 10.1021/bc00035a003. [DOI] [PubMed] [Google Scholar]
- de Bizemont T., Duval-Valentin G., Sun J. S., Bisagni E., Garestier T., Hélène C. Alternate strand recognition of double-helical DNA by (T,G)-containing oligonucleotides in the presence of a triple helix-specific ligand. Nucleic Acids Res. 1996 Mar 15;24(6):1136–1143. doi: 10.1093/nar/24.6.1136. [DOI] [PMC free article] [PubMed] [Google Scholar]