title: Phototriggered DNA complexation and compaction using poly(vinyl alcohol) carrying a malachite green moiety.
abstract: Photoinduced DNA compaction was performed using the interaction of DNA with a photoresponsive random copolymer of poly(vinyl alcohol) carrying a malachite green moiety (PVAMG). Although PVAMG does not have any affinity for DNA under dark conditions, it undergoes photoionization upon exposure to UV light, consequently resulting in a cationic binding site for DNA. Electrophoresis results demonstrated that irradiation of PVAMG retarded the DNA bands due to their complexation, whereas the bands remained unchanged under dark conditions. The binding of PVAMG to DNA occurs at a cationic site/DNA phosphate ratio of approximately 0.036. Single-molecule observations of DNA by fluorescence microscopy revealed that irradiation of PVAMG induced a coil-globule transition in the DNA molecule. Complete compaction of DNA has been accomplished at a cationic site/DNA phosphate ratio >8.0, indicating that PVAMG offers an effective system to photochemically trigger DNA compaction.
authors.affiliation: Department of Chemical Engineering, Nara National College of Technology, Yata 22, Yamato-koriyama, Nara 639-1080, Japan. ryoko@chem.nara-k.ac.jp
authors.forename: Ryoko M
authors.initials: RM
authors.lastname: Uda
authors.forename: Minami
authors.initials: M
authors.lastname: Ohshita
mesh_terms: D000818:Animals; D002417:Cattle; D004247:DNA / Q000737:chemistry*; D015394:Molecular Structure; D055668:Photochemical Processes; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D012394:Rosaniline Dyes / Q000737:chemistry*
chemical_list: D012394:Rosaniline Dyes; C005095:malachite green; D011142:Polyvinyl Alcohol; D004247:DNA; C427203:calf thymus DNA