Metal ion-directed cooperative DNA binding of small molecules.
Compound (1), which consists of an oxine and a pyridinium group, was synthesized as a metal-responsive DNA binding ligand. Two 1s coordinate to a Cu(II) to form a stable dimer (1(2)-Cu), even in the presence of DNA. The binding of 1 with sonicated calf thymus DNA was enhanced by ca. 10(3) times after forming the dimer; the binding constants were estimated to be 3.2 x 10(4)M(-1) and 2.4 x 10(7)M(-1) in the absence and the presence, respectively, of a half mole of Cu(II). The enormous acceleration of the binding is partly attributed to the generation of a dicationic charge by the formation of the dimer. High cooperativity between dimers could be also responsible; dimers would gather along the duplex as a template to form 1D spiral aggregates.
Ihara
Toshihiro
T
Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University, Kurokami, Kumamoto 860-8555, Japan. toshi@chem.kumamoto-u.ac.jp <toshi@chem.kumamoto-u.ac.jp>
Ikegami
Takashi
T
Fujii
Tomohiro
T
Kitamura
Yusuke
Y
Sueda
Shinji
S
Takagi
Makoto
M
Jyo
Akinori
A
D000818:Animals; D002412:Cations / Q000737:chemistry; D002417:Cattle; D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D019281:Dimerization; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008670:Metals / Q000737:chemistry*; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet
D002412:Cations; D008024:Ligands; D008670:Metals; D003300:Copper; D004247:DNA; C427203:calf thymus DNA