Guanine damage by singlet oxygen from SYBR Green I in liquid crystalline DNA

• Published in: Organic & biomolecular chemistry Vol. 18; no. 36; pp. 7183 - 7187
• Main Authors: Sakurai, Shunsuke, Jo, Kento, Kinoshita, Hikari, Esumi, Mayu, Tanaka, Makiko
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 23.09.2020
• Subjects: Addition polymerization; Benzothiazoles - chemistry; Crystal structure; Crystallinity; Damage; Deoxyribonucleic acid; Diamines - chemistry; DNA; DNA - chemistry; DNA Damage; Fluorescence; Fluorescence microscopy; Fluorescent Dyes - chemistry; Guanine; Guanine - chemistry; High-performance liquid chromatography; Irradiation; Liquid chromatography; Liquid crystals; Liquid Crystals - chemistry; Oligonucleotides; Organic Chemicals - chemistry; Oxygen; Polymers; Quinolines - chemistry; Radiation; Singlet oxygen; Singlet Oxygen - chemistry
• ISSN: 1477-0520; 1477-0539; 1477-0539
• DOI: 10.1039/d0ob01723j

It is known that double-stranded DNA (dsDNA) turns into a liquid crystalline phase by the addition of a high concentration of polymer with salt. SYBR Green I (SG) is a well-known sensitive fluorescent stain for dsDNA, and is intercalated in liquid crystalline DNA. Formation of the liquid crystalline dsDNA-SG complex has been confirmed by CD spectral measurements, fluorescence spectral measurements and confocal fluorescence microscopy. SG in dsDNA was also used as a singlet oxygen generator. We conducted photoirradiation experiments using three kinds of 42-mer oligonucleotides with SG. The amount of guanine decomposition by selective irradiation of SG was analyzed using HPLC after digestion of dsDNA in each sample solution. We found that singlet oxygen produced in liquid crystalline DNA promoted guanine damage much more efficiently than in homogeneous solution. Efficiency of guanine damage by singlet oxygen generated from photoexcited SYBR Green I was remarkably promoted in liquid crystalline DNA.