Carregant...
Fitxers
Tipus de document
ArticleVersió
Versió publicadaData de publicació
Llicència de publicació
Si us plau utilitzeu sempre aquest identificador per citar o enllaçar aquest document: https://hdl.handle.net/2445/137039
Study of conformational transitions of i-motif DNA using time-resolved fluorescence and multivariate analysis methods
Títol de la revista
Director/Tutor
ISSN de la revista
Títol del volum
Recurs relacionat
Resum
Recently, the presence of i-motif structures at C-rich sequences in human cells and their regulatory functions have been demonstrated. Despite numerous steady-state studies on i-motif at neutral and slightly acidic pH, the number and nature of conformation of this biological structure are still controversial. In this work, the fluorescence lifetime of labelled molecular beacon i-motif-forming DNA sequences at different pH values is studied. The influence of the nature of bases at the lateral loops and the presence of a Watson-Crick-stabilized hairpin are studied by means of time-correlated single-photon counting technique. This allows characterizing the existence of several conformers for which the fluorophore has lifetimes ranging from picosecond to nanosecond. The information on the existence of different i-motif structures at different pH values has been obtained by the combination of classical global decay fitting of fluorescence traces, which provides lifetimes associated with the events defined by the decay of each sequence and multivariate analysis, such as principal component analysis or multivariate curve resolution based on alternating least squares. Multivariate analysis, which is seldom used for this kind of data, was crucial to explore similarities and differences of behaviour amongst the different DNA sequences and to model the presence and identity of the conformations involved in the pH range of interest. The results point that, for i-motif, the intrachain contact formation and its dissociation show lifetimes ten times faster than for the open form of DNA sequences. They also highlight that the presence of more than one i-motif species for certain DNA sequences according to the length of the sequence and the composition of the bases in the lateral loop.
Matèries
Matèries (anglès)
Citació
Citació
BENABOU ZDAOU, Sanae, RUCKEBUSCH, Cyril, SLIWA, Michel, AVIÑÓ ANDRÉS, Anna, ERITJA I CASADELLÀ, Ramon, GARGALLO GÓMEZ, Raimundo, JUAN CAPDEVILA, Anna de. Study of conformational transitions of i-motif DNA using time-resolved fluorescence and multivariate analysis methods. _Nucleic Acids Research_. 2018. [consulta: 14 de gener de 2026]. ISSN: 0305-1048. [Disponible a: https://hdl.handle.net/2445/137039]