title: Effect of C(60) fullerene on the duplex formation of i-motif DNA with complementary DNA in solution.
abstract: The structural effects of fullerene on i-motif DNA were investigated by characterizing the structures of fullerene-free and fullerene-bound i-motif DNA, in the presence of cDNA and in solutions of varying pH, using circular dichroism and synchrotron small-angle X-ray scattering. To facilitate a direct structural comparison between the i-motif and duplex structures in response to pH stimulus, we developed atomic scale structural models for the duplex and i-motif DNA structures, and for the C(60)/i-motif DNA hybrid associated with the cDNA strand, assuming that the DNA strands are present in an ideal right-handed helical conformation. We found that fullerene shifted the pH-induced conformational transition between the i-motif and the duplex structure, possibly due to the hydrophobic interactions between the terminal fullerenes and between the terminal fullerenes and an internal TAA loop in the DNA strand. The hybrid structure showed a dramatic reduction in cyclic hysteresis.
authors.affiliation: Pohang Accelerator Laboratory, Department of Chemistry, National Research Lab for Polymer Synthesis and Physics, Center for Electro-Photo Behaviors in Advanced Molecular Systems, Division of Advanced Materials Science, Polymer Research Institute, and BK School of Molecular Science, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
authors.forename: Kyeong Sik
authors.initials: KS
authors.lastname: Jin
authors.forename: Su Ryon
authors.initials: SR
authors.lastname: Shin
authors.forename: Byungcheol
authors.initials: B
authors.lastname: Ahn
authors.forename: Sangwoo
authors.initials: S
authors.lastname: Jin
authors.forename: Yecheol
authors.initials: Y
authors.lastname: Rho
authors.forename: Heesoo
authors.initials: H
authors.lastname: Kim
authors.forename: Seon Jeong
authors.initials: SJ
authors.lastname: Kim
authors.forename: Moonhor
authors.initials: M
authors.lastname: Ree
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000187:drug effects*; D018076:DNA, Complementary / Q000737:chemistry* / Q000378:metabolism*; D037741:Fullerenes / Q000494:pharmacology*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation / Q000187:drug effects*; D053838:Scattering, Small Angle; D012996:Solutions; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D018076:DNA, Complementary; D037741:Fullerenes; D012996:Solutions; D004247:DNA