title: Wrapping/unwrapping transition of double-stranded DNA in DNA-nanosphere complexes induced by multivalent anions.
abstract: Wrapping and unwrapping behaviors of double-stranded DNA around a positively charged nanosphere in solution are studied by using the coarse-grained molecular dynamics (CGMD) simulation method. When monovalent, divalent and trivalent anions are added to the DNA-nanosphere complex solution, double-stranded DNA binds with a nanosphere owing to strong electrostatic attraction. However, when tetravalent anions are added to the DNA-nanosphere complex solution, local charge inversion is observed for a high anion concentration of tetravalent anions and the double-stranded DNA can be unwrapped from the nanosphere because of the local charge inversion near the nanosphere. Moreover, the helical structure of DNA is damaged when double-stranded DNA wraps around the nanosphere and the helical structure can be rebuilt when the double-stranded DNA unwraps from the nanosphere. This study can help us understand how to control the release of DNA in DNA-nanosphere complexes.
authors.affiliation: Department of Physics, Zhejiang University, Hangzhou, 310027, China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Chai
authors.forename: Yangwei
authors.initials: Y
authors.lastname: Jiang
authors.forename: Yaoyang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Linli
authors.initials: L
authors.lastname: He
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.forename: Linxi
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000838:Anions / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D054118:Nanospheres / Q000737:chemistry*
chemical_list: D000838:Anions; D004247:DNA