Benzothiazole derivatives as fluorescent "light-up" probes for duplex and quadruplex DNA.

Benzothiazole derivatives as fluorescent "light-up" probes for duplex and quadruplex DNA.
Biochimie. 2019 Apr 22;:
Authors: Turaev AV, Tsvetkov VB, Tankevich MV, Smirnov IP, Aralov AV, Pozmogova GE, Varizhuk AM
Abstract
Analogs of benzothiazole orange (BO) with one, two or three methylbenzothiazolylmethylidene substituents in the 1-methylpyridinium ring were obtained from the respective picolinium, lutidinium or collidinium salts. Fluorescence parameters of the known and new dyes in complexes with various DNA structures, including G-quadruplexes (G4s) and i-motifs (IMs), were analyzed. All dyes efficiently distinguished G4s and ss-DNA. The bi- and tri-substituted derivatives had basically similar distributions of relative fluorescence intensities. The mono-substituted derivatives exhibited enhanced sensitivity to parallel G4s. All dyes were particularly sensitive to a G4 structure with an additional duplex module (the thrombin-binding aptamer TBA31), presumably due to a distinct binding pattern (interaction with the junction between the two modules). In particular, BO showed a strong (170-fold) enhancement in fluorescence quantum yield in complex with TBA31 compared to the free dye. The fluorescence quantum yields of the bi-substituted derivative in complex with well-characterized G4s from oncogene promoters were comparable to those of ThT. The mono/bi-substituted derivatives should be considered as possible light-up probes for G4 fo...

Source: Biochimie - April 21, 2019 Category: Biochemistry Authors: Turaev AV, Tsvetkov VB, Tankevich MV, Smirnov IP, Aralov AV, Pozmogova GE, Varizhuk AM Tags: Biochimie Source Type: research