Bis(pyrrolecarboxamide) linked to intercalating chromophore oxazolopyridocarbazole (OPC): selective binding to DNA and polynucleotides
| Autor: | Gilles Gosselin, Jacques Paoletti, Frédéric Subra, Jeanne Pager, Jean Louis Imbach, D Mrani, S. Carteau, Claude Paoletti, Christian Auclair |
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| Rok vydání: | 1991 |
| Předmět: |
DNA
Bacterial Free Radicals Base pair Stereochemistry Molecular Sequence Data Carbazoles EcoRI Fluorescence spectrometry Nucleic Acid Denaturation Biochemistry chemistry.chemical_compound Polydeoxyribonucleotides Poly dA-dT Escherichia coli Hydroxides Binding site Base Sequence Molecular Structure biology Hydroxyl Radical Netropsin DNA Restriction Enzymes Chromophore Binding constant Kinetics stomatognathic diseases nervous system chemistry Polynucleotide biology.protein Regression Analysis Mathematics Plasmids |
| Zdroj: | Biochemistry. 30:1642-1650 |
| ISSN: | 1520-4995 0006-2960 |
| Popis: | We have investigated some properties related to interaction with DNA and recognition of AT-rich sequences of netropsin-oxazolopyridocarbazole (Net-OPC) (Mrani et al., 1990), which is a hybrid groove-binder-intercalator. The hybrid molecule Net-OPC binds to poly[d(A-T)] at two different sites with Kapp values close to 7 x 10(6) and 6 x 10(8) M-1 (100 mM NaCl, pH 7.0). Data obtained from melting experiments are in agreement with these values and indicate that Net-OPC displays a higher binding constant to poly[d(A-T)] than does netropsin. On the basis of viscometric and energy transfer data, the binding of Net-OPC to poly[d(A-T)] is suggested to involve both intercalation and external binding of the OPC chromophore. In contrast, on poly[d(G-C)], Net-OPC binds to a single type of site composed of two base pairs in which the OPC chromophore appears to be mainly intercalated. The binding constant of Net-OPC to poly[d(G-C)] was found to be about 350-fold lower than that of the high-affinity binding site in poly[d(A-T)]. As evidenced by footprinting data, Net-OPC selectively recognizes TTAA and CTT sequences and strongly protects the 10-bp AT-rich DNA region 3'-TTAAGAACTT-5' containing the EcoRI site. The binding of Net-OPC to this sequence results in a strong and selective inhibition of the activity of the restriction endonuclease EcoRI on the plasmid pBR322 as substrate. The extent of inhibition of the rate constant of the first strand break catalyzed by the enzyme is about 100-fold higher than the one observed in the presence of netropsin under similar experimental conditions. |
| Databáze: | OpenAIRE |
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