title: pH-Induced conformational change and dimerization of DNA chains investigated by analytical ultracentrifugation.
abstract: pH-induced conformational change of i-motif DNA has been studied by analytical ultracentrifugation. As pH increases, the hydrodynamic radius of individual DNA chains in aqueous solutions prepared by being heat-treated suddenly increases while the molar mass is constant, indicating that the conformation changes from an i-motif to a random coil. When DNA concentrations are higher than 1.0 μM, relatively stable dimers are formed as pH sharply decreases from 7.5 to 4.5. Moreover, the weight percentage of the dimers increases with the initial DNA concentration. The study can help to understand the functions of the telomeres containing repeated cytosine-rich sequences and to develop DNA-based devices.
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China , Hefei, Anhui 230026, China.
authors.forename: Sha
authors.initials: S
authors.lastname: Wu
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Wang
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Ye
authors.forename: Guangzhao
authors.initials: G
authors.lastname: Zhang
mesh_terms: D004247:DNA / Q000737:chemistry*; D004058:Diffusion; D019281:Dimerization; D006358:Hot Temperature; D057446:Hydrodynamics; D006863:Hydrogen-Ion Concentration; D009690:Nucleic Acid Conformation; D012996:Solutions / Q000737:chemistry; D013997:Time Factors; D014461:Ultracentrifugation; D014867:Water / Q000737:chemistry
chemical_list: D012996:Solutions; D014867:Water; D004247:DNA