Sulfonated Pyrene as a Photoregulator for Single‐Stranded DNA Looping

Abstract

Controlling the conformationa nd functiono fb iomolecules through photoregulators holds great promise as a spatiotemporally controllable tool for disease control.I na ddition, introducing photoregulators into biomoleculesh as also found applicationsi nc onstructings martn anomaterials. In spite of the astonishing advances that have been made in the past few years, realizing highly controllable and efficient regulation over the conformation and functiono fb iomolecules under physiological conditionsi ss till challenging. Herein,s ulfonated pyrene SPy was synthesized and used as ap hotoregulator to control the looping of single-stranded DNAs (ssDNAs) in aqueous solution.Due to its water solubility, SPy merits use in the study of biomolecules in aqueous solution.T he looping of the doubly SPy-modified ssDNAs is stimulated by irradiation and regulated by SPy.P hotoionization generatest he radicalc ation of SPy (SPyC + ). The association of SPyC + + with its neutralc ounterpart, SPy,g ives rise to the dimer radicalc ation of SPy (SPy 2 C + + ). During the association process, the stabilization energy released to form SPy 2 C + + provides ad riving force for the looping of ssDNAs. Conversely,t he formed loop conformationsw ere trapped by the formation of SPy 2 C + + ,a nd this allowed the looping dynamics to be investigated. The results reported herein suggest potential of SPy as ap hotoregulator for controlling the conformationa nd function of biomolecules under physiological conditions.[a] J.[a] Immediately formed SPy 2 C + + component. P static = DOD t = 10 ns /DOD max .

Control of Triplet Blinking Using Cyclooctatetraene to Access the Dynamics of Biomolecules at the Single‐Molecule Level

“…When comparing (dA) n spacer composed of purine bases possessing two‐ringed structure with (dT) n spacer composed of pyrimidine bases possessing a single‐ringed structure, the former having a stronger π‐stacking interaction showed a τ OFF value larger than that of the latter with the same length (Figure 2 c). [67, 68] The length and sequence dependencies of τ OFF demonstrate that the triplet blinking of ATTO 647N, which is triggered by the collision‐induced TTET reaction between 3 ATTO 647N* and COT, is governed by the dynamics of the ssDNA spacer. Therefore, by measuring the triplet blinking of ATTO 647N the dynamics of biomolecules can be accessed in the time range of 10 −6 –10 −3 s with a tiny amount of sample (tens of fmol in this work).…”