Effective control of the intrinsic DNA morphology by photosensitive polyamines
Marco Deiana, Ziemowit Poladek, Katarzyna Matczyszyn, Piotr Mlynarz, Malcolm Buckle, Marek Samoc
Journal of Materials Chemistry B
Non-viral vectors for gene therapy such as DNA-cationic probe complexes offer important bio-safety advantages over viral approaches, due to their reduced pathogenicity, immunogenicity and cytotoxicity. In the present study we examine two polycationic water-soluble azobenzene derivatives (bis-Azo-2N and bis-Azo-3N) containing different linear unsubstituted polyamine moieties and we demonstrate the ability of such photochromes to destabilize the intrinsic B-DNA secondary structure in a concentration-dependent manner. Furthermore, through a detailed series of biophysical experiments, varying the photochrome conformation, temperature, salt and DNA concentration, we provide a detailed insight into the azobenzene-DNA binding pathway (Ka : bis-Azo-2N(trans)-DNA = 5.3 ± 0.3 × 104 M -1, Ka : bis-Azo-2N(cis)-DNA = 2.6 ± 0.2 × 104 M -1, Ka : bis-Azo-3N(trans)-DNA = 7.1 ± 0.4 × 104 M -1 and Ka : bis-Azo-3N(cis)-DNA = 5.1 ± 0.4 × 104 M -1) establishing the versatility of such materials as promising candidates for use in non-viral gene delivery systems.
Circular dichroism, Induced CD DNA structure, Ligand binding, Biochemistry, Materials