EVIDENCE FOR DAPI INTERCALATION IN CG SITES OF DNA OLIGOMER [D(CGACGTCG)](2) - A

2020-03-26 14:16:09

DNA binding NMR DAPI CGACGTCG

责任者: TROTTA, E;DAMBROSIO, E;RAVAGNAN, G;PACI, M 单位: UNIV ROMA TOR VERGATA,DIPARTIMENTO SCI & TECNOL CHIM,ROME,ITALY. 来源出处: NUCLEIC ACIDS RESEARCH, v 23, APR 25 1995, p 1333- 1340 摘要: The interaction between 4,6-diamidino-2-phenylindole (DAPI) and the DNA oligomer [d(CGACGTCG)](2) has been investigated by proton one- and two-dimensional NMR spectroscopy in solution, Compared with the minor groove binding of the drug to [d(GCGATCGC)](2), previously studied by NMR spectroscopy, the interaction of DAPI with [d(CGACGTCG)](2) appears markedly different and gives results typical of a binding mechanism by intercalation. C:G imino proton signals of the [d(CGACGTCG)](2) oligomer as well as DAPI resonances appear strongly upfield shifted and sequential dipolar connectivities between cytosine and guanine residues show a clear decrease upon binding, Moreover, protons lying in both the minor and major grooves of the DNA double helix appear involved in the interaction, as evidenced principally by intermolecular drug-DNA NOEs, In particular, the results indicate the existence of two stereochemically non-equivalent intercalation binding sites located in the central and terminal adjacent C:G base pairs of the palindromic DNA sequence, Different lifetimes of the complexes were also observed for the two sites of binding, Moreover, due to the fast exchange on the NMR timescale between free and bound species, different interactions in dynamic equilibrium with the observed intercalative bindings were not excluded. 关键词: DIAMOND FILMS; TRIBOLOGY; LASER IRRADIATION; SEQUENTIAL RESONANCE ASSIGNMENTS; MINOR-GROOVE BINDING; 4,6-DIAMIDINO-2-PHENYLINDOLE DAPI; H-1-NMR SPECTRA; NUCLEIC-ACIDS; 4,6-DIAMIDINO-2-PHENYLINDOLE DAPI; H-1-NMR SPECTRA; NUCLEIC-ACIDS; NANOGRAM QUANTITIES; PROTON RESONANCES; AQUEOUS-SOLUTION; SPECTROSCOPY; NANOGRAM QUANTITIES; PROTON RESONANCES; AQUEOUS-SOLUTION; SPECTROSCOPY; RNA RNA