Volume 63, Issue 14 e202319516
Research Article

Site-Selective Photo-Crosslinking of Stilbene Pairs in a DNA Duplex Mediated by Ruthenium Photocatalyst

Dr. Hiromu Kashida

Corresponding Author

Dr. Hiromu Kashida

Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University Furo-cho, Chikusa-ku, Nagoya, 464-8603 Japan

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Hidenori Azuma

Hidenori Azuma

Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University Furo-cho, Chikusa-ku, Nagoya, 464-8603 Japan

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Dr. Hikaru Sotome

Dr. Hikaru Sotome

Division of Frontier Materials Science and, Center for Advanced Interdisciplinary Research, Graduate School of Engineering Science, Osaka University 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531 Japan

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Prof. Dr. Hiroshi Miyasaka

Prof. Dr. Hiroshi Miyasaka

Division of Frontier Materials Science and, Center for Advanced Interdisciplinary Research, Graduate School of Engineering Science, Osaka University 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531 Japan

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Prof. Dr. Hiroyuki Asanuma

Corresponding Author

Prof. Dr. Hiroyuki Asanuma

Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University Furo-cho, Chikusa-ku, Nagoya, 464-8603 Japan

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First published: 28 January 2024
Citations: 1

Graphical Abstract

A novel method to site-specifically crosslink DNA duplex upon visible light irradiation. Ru complex on the third strand catalyzed [2+2] photocycloaddition of stilbene moieties via triplet-triplet energy transfer. Site specificity is realized owing to steep distance dependence of the energy transfer. This method will be useful in construction of complex photoresponsive DNA circuits, nanodevices and biological tools.

Abstract

We herein report a method for site-selective photo-crosslinking of a DNA duplex. A stilbene pair was introduced into a DNA duplex and a ruthenium complex was conjugated with a triplex-forming oligonucleotide. We demonstrated that [2+2] photocycloaddition of the stilbene pair occurred upon irradiation with visible light when the ruthenium complex was in close proximity due to triplex formation. No reaction occurred when the ruthenium complex was not in proximity to the stilbene pair. The wavelength of visible light used was of lower energy than the wavelength of UV light necessary for direct excitation of stilbene. Quantum chemical calculation indicated that ruthenium complex catalyzed the photocycloaddition via triplet-triplet energy transfer. Site selectivity of this photo-crosslinking system was evaluated using a DNA duplex bearing two stilbene pairs as a substrate; we showed that the site of crosslinking was precisely regulated by the sequence of the oligonucleotide linked to the ruthenium complex. Since this method does not require orthogonal photoresponsive molecules, it will be useful in construction of complex photoresponsive DNA circuits, nanodevices and biological tools.

Conflict of interests

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available in the supplementary material of this article.

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