Base Pair Sensitivity and Enhanced ON/OFF Ratios of DNA-Binding: Donor-Acceptor-Donor Fluorophores
Artikel i vetenskaplig tidskrift, 2013

The photophysical properties of two recently reported live cell compatible, DNA-binding dyes, 4,6-bis(4-(4-methylpiperazin-1-yl)phenyl)pyrimidin-2-ol, 1, and [1,3-bis[4-(4-methylpiperazin-1-yl)phenyl]-1,3-propandioato-kappa O, kappa O']difluoroboron, 2, are characterized. Both dyes are quenched in aqueous solutions, while binding to sequences containing only AT pairs enhances the emission. Binding of the dyes to sequences containing only GC pairs does not produce a significant emission enhancement, and for sequences containing both AT and GC base pairs, emission is dependent on the length of the AT pair tracts. Through emission lifetime measurements and analysis of the dye redox potentials, photoinduced electron transfer with GC pairs is implicated as a quenching mechanism. Binding of the dyes to AT-rich regions is accompanied by bathochromic shifts of 26 and 30 nm, respectively. Excitation at longer wavelengths thus increases the ON/OFF ratio of the bound probes significantly and provides improved contrast ratios in solution as well as in fluorescence microscopy of living cells.


J. Wilson

University of Miami

Jens Wigenius

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

D. R. G. Pitter

University of Miami

Y. H. Qiu

University of Miami

Maria Abrahamsson

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Fredrik Westerlund

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Journal of Physical Chemistry B

1520-6106 (ISSN) 1520-5207 (eISSN)

Vol. 117 40 12000-12006


Nanovetenskap och nanoteknik (SO 2010-2017, EI 2018-)





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