title: Disassembly of DNA-ligand on mica surface: atomic force microscopy studies.
abstract: Disassembly of DNA-ligands, including DNA-methylene blue (MB) complex and DNA-Co(phen)(3) (3+) complex on mica surface, were investigated by atomic force microscopy (AFM). The disassembly of these complexes occurred after they were immersed in ultra-pure water. AFM results showed that the disassembly depended strongly on bridge ions that were used to immobilize the complex onto mica surface, DNA species and ligands. When Mg(2+) was used as the bridge ion, the DNA-MB complex was completely disassembled because of the weak interactions between Mg(2+) and DNA's bases or mica surface. Although if Co(2+) was used as the bridge ion, the disassembly of the DNA-MB complex mainly depended on the species and shape of DNA. For plasmid DNA pBR 322, plasmid DNA pUC 18 and the linear DNA pBR 322/PstI, the degree of disassembly was gradually increased. Whereas if Co(phen)(3) (3+) was chosen as the ligand, the disassembly of the DNA-Co(phen)(3) (3+) complex was almost blocked because Co(phen)(3) (3+) could hardly diffuse into the ultra-pure water. This obtained information may be useful for practical application of the AFM imaging of biological molecules, especially in liquid.
authors.affiliation: College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China.
authors.forename: Y
authors.initials: Y
authors.lastname: Song
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: Zhao
authors.forename: W
authors.initials: W
authors.lastname: Lian
authors.forename: Z
authors.initials: Z
authors.lastname: Li
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D008024:Ligands; D008274:Magnesium / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry; D018625:Microscopy, Atomic Force; D009942:Organometallic Compounds / Q000737:chemistry; D010618:Phenanthrolines / Q000737:chemistry; D010957:Plasmids / Q000737:chemistry; D013053:Spectrophotometry; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D008024:Ligands; D009942:Organometallic Compounds; D010618:Phenanthrolines; C414956:triphenanthrolinecobalt(II); D014867:Water; D004247:DNA; D008274:Magnesium; D008751:Methylene Blue; C011934:mica