title: Photochromic switching of the DNA helicity induced by azobenzene derivatives.
abstract: The photochromic properties of azobenzene, involving conformational changes occurring upon interaction with light, provide an excellent tool to establish new ways of selective regulation applied to biosystems. We report here on the binding of two water-soluble 4-(phenylazo)benzoic acid derivatives (Azo-2N and Azo-3N) with double stranded DNA and demonstrate that the photoisomerization of Azo-3N leads to changes in DNA structure. In particular, we show that stabilization and destabilization of the B-DNA secondary structure can be photochemically induced in situ by light. This photo-triggered process is fully reversible and could be an alternative pathway to control a broad range of biological processes. Moreover, we found that the bicationic Azo-3N exhibited a higher DNA-binding constant than the monocationic Azo-2N pointing out that the number of positive charges along the photosensitive polyamines chain plays a pivotal role in stabilizing the photochrome-DNA complex.
authors.affiliation: Advanced Materials Engineering and Modelling Group, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland.
authors.forename: Marco
authors.initials: M
authors.lastname: Deiana
authors.affiliation: Department of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland.
authors.forename: Ziemowit
authors.initials: Z
authors.lastname: Pokladek
authors.affiliation: Advanced Materials Engineering and Modelling Group, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Olesiak-Banska
authors.affiliation: Department of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Młynarz
authors.affiliation: Advanced Materials Engineering and Modelling Group, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Samoc
authors.affiliation: Advanced Materials Engineering and Modelling Group, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Matczyszyn
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D059371:DNA, B-Form / Q000737:chemistry*; D008027:Light; D010777:Photochemistry / Q000379:methods; D017433:Protein Structure, Secondary
chemical_list: D001391:Azo Compounds; D059371:DNA, B-Form; C009850:azobenzene