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Disassembly of DNA–ligand on mica surface: atomic force microscopy studies
Author(s) -
SONG Y.,
WANG L.,
ZHAO S.,
LIAN W.,
LI Z.
Publication year - 2009
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.2009.03154.x
Subject(s) - mica , dna , atomic force microscopy , chemistry , molecule , crystallography , ligand (biochemistry) , ion , biophysics , nanotechnology , materials science , biochemistry , biology , organic chemistry , receptor , composite material
Summary 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.