Two-dimensional NMR spectroscopy has been applied to study the solution binding of 4',6-diamidino-2-phenylindole (DAPI) to synthetic DNA duplex [d(GCGATCGC)]2. The structure of the complex at a molar ratio of 1:1 drug:duplex has been investigated. NMR results indicate that DAPI binds selectively in the minor groove of the DNA region containing only two A:T base pairs. The results disagree with conclusions drawn from footprinting experiments and show that the presence of the G3NH2 group in the minor groove does not prevent the binding. A molecular model is proposed that closely resembles the crystal structure previously published for the interaction of DAPI with the dodecamer [d(CGCGAATTCGCG)]2, containing four A:T base pairs in the binding site. In this model, DAPI lies in the minor groove, nearly isohelical, with its aromatic rings adjacent to H4' protons of T5 and C6 deoxyribose and the NH indole group oriented toward the DNA axis. The binding does not perturb the B-type conformation of the duplex, and the DNA oligomer conserves its 2-fold symmetry, indicating that fast exchange dynamics exist between the two stereochemically equivalent binding sites of the palindromic sequence. The binding constant and the exchange rate between free and bound species were also measured by NMR spectroscopy.

Trotta, E., D'Ambrosio, E., Del Grosso, N., Ravagnan, G., Cirilli, M., Paci, M. (1993). 1H NMR study of [d(GCGATCGC)]2 and its interaction with minor groove binding 4',6-diamidino-2-phenylindole. THE JOURNAL OF BIOLOGICAL CHEMISTRY, 268(6), 3944-3951.

1H NMR study of [d(GCGATCGC)]2 and its interaction with minor groove binding 4',6-diamidino-2-phenylindole

PACI, MAURIZIO
1993-02-25

Abstract

Two-dimensional NMR spectroscopy has been applied to study the solution binding of 4',6-diamidino-2-phenylindole (DAPI) to synthetic DNA duplex [d(GCGATCGC)]2. The structure of the complex at a molar ratio of 1:1 drug:duplex has been investigated. NMR results indicate that DAPI binds selectively in the minor groove of the DNA region containing only two A:T base pairs. The results disagree with conclusions drawn from footprinting experiments and show that the presence of the G3NH2 group in the minor groove does not prevent the binding. A molecular model is proposed that closely resembles the crystal structure previously published for the interaction of DAPI with the dodecamer [d(CGCGAATTCGCG)]2, containing four A:T base pairs in the binding site. In this model, DAPI lies in the minor groove, nearly isohelical, with its aromatic rings adjacent to H4' protons of T5 and C6 deoxyribose and the NH indole group oriented toward the DNA axis. The binding does not perturb the B-type conformation of the duplex, and the DNA oligomer conserves its 2-fold symmetry, indicating that fast exchange dynamics exist between the two stereochemically equivalent binding sites of the palindromic sequence. The binding constant and the exchange rate between free and bound species were also measured by NMR spectroscopy.
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore BIO/10
English
Con Impact Factor ISI
Models, Molecular; Protons; DNA; Base Sequence; Nucleic Acid Conformation; Molecular Sequence Data; Indoles; Magnetic Resonance Spectroscopy; Polydeoxyribonucleotides; Fluorescent Dyes
http://www.jbc.org/content/268/6/3944.full.pdf
Trotta, E., D'Ambrosio, E., Del Grosso, N., Ravagnan, G., Cirilli, M., Paci, M. (1993). 1H NMR study of [d(GCGATCGC)]2 and its interaction with minor groove binding 4',6-diamidino-2-phenylindole. THE JOURNAL OF BIOLOGICAL CHEMISTRY, 268(6), 3944-3951.
Trotta, E; D'Ambrosio, E; Del Grosso, N; Ravagnan, G; Cirilli, M; Paci, M
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/15377
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