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Titolo:
4 ',6-Diamidino-2-phenylindole (DAPI) interacts with rare structures of GCpolymers
Autore:
Barcellona, ML; Chen, Y; Muller, JD; Gratton, E;
Indirizzi:
Univ Catania, Dept Biochem & Mol Biol, I-95125 Catania, Italy Univ Catania Catania Italy I-95125 em & Mol Biol, I-95125 Catania, Italy Univ Illinois, Fluorescence Dynam Lab, Urbana, IL 61801 USA Univ IllinoisUrbana IL USA 61801 escence Dynam Lab, Urbana, IL 61801 USA
Titolo Testata:
EUROPEAN BIOPHYSICS JOURNAL WITH BIOPHYSICS LETTERS
fascicolo: 2, volume: 30, anno: 2001,
pagine: 98 - 109
SICI:
0175-7571(2001)30:2<98:4'(IWR>2.0.ZU;2-5
Fonte:
ISI
Lingua:
ENG
Soggetto:
FLUORESCENCE CORRELATION SPECTROSCOPY; MINOR-GROOVE BINDING; ELECTRIC LINEAR DICHROISM; CROSS-CORRELATION; FLUCTUATION SPECTROSCOPY; LIFETIME DISTRIBUTIONS; DNA DODECAMER; COMPLEX; MOLECULES; INTERCALATION;
Keywords:
fluorescence correlation spectroscopy aggregation; fluorescence lifetime; DAPI/DNA interactions;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
62
Recensione:
Indirizzi per estratti:
Indirizzo: Barcellona, ML Univ Catania, Dept Biochem & Mol Biol, Viale A Doria 6, I-95125 Catania, Italy Univ Catania Viale A Doria 6 Catania Italy I-95125 , Italy
Citazione:
M.L. Barcellona et al., "4 ',6-Diamidino-2-phenylindole (DAPI) interacts with rare structures of GCpolymers", EUR BIOPHYS, 30(2), 2001, pp. 98-109

Abstract

The binding of 4 ' ,6-diamidino-2-phenylindole (DAPI) to double-stranded GC polymers either in the alternating or in homopolymer sequence was investigated using fluorescence techniques. We employed fluctuation correlation spectroscopy, which measures the diffusion coefficient of fluorescent particles, to demonstrate that the fluorescence was originating from relatively slowly diffusing entities. These entities display a very large heterogeneity of diffusing coefficients, indicating that molecular aggregation is extensive in our samples. We used frequency domain fluorometry to characterize thefluorescence lifetime of the species, while varying the GC polymer-dye coverage systematically. At very low coverage we observed a relatively bright fluorescent component with a lifetime value of approximately 4 ns. The stoichiometry of binding of this bright species was such that it can only arisefrom rare molecular structures, either unusual loops or large molecular aggregates. The amount and characteristics of this bright fluorescent component were different between the home and the alternating polymer, indicating that the difference in sequence of the two polymers is responsible for the different aggregates which are then detected in the fluorescence experiment. At large GC polymer coverage we observed a relatively wide distribution of fluorescent species with short lifetime values, in the range between 0.12and 0.2ns. Given the stoichiometry of binding of this fluorescent component, we concluded that it could arise either from intercalative and/or non-specific binding to the DNA double-stranded molecules. We comment on the origin of the rare but brightly fluorescent binding sites and discuss the potential to detect such unusual DNA structures.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/09/20 alle ore 22:52:30