Interaction of bis(ethylene)tin(bis(salicylidene)ethylenediamine) with DNA.
The fluorescence spectral characteristics and interaction of bis(ethylene)tin(bis(salicylidene)ethylenediamine) [Et2Sn(salen)] with DNA are described. The polarity of the solvent has a strong effect on the fluorescence characteristics of Et2Sn(salen). Et2Sn(salen) bound to DNA showed a marked decrease in the fluorescence intensity with a bathochromic shift of the excitation and emission peaks. A hypochromism in the UV absorption spectra was also observed. KI quenching and competitive binding to DNA between Et2Sn(salen) and ethidium bromide (EB) were studied in connection with other experimental observations to show that the interactive model between Et2Sn(salen) and DNA is an intercalative one. The pH and salt effect on the fluorescence properties was also investigated. The intrinsic binding constant was estimated to be 1.071 x 10(5) mol L(-1) in base pairs and the binding site number is 1.98, respectively. A linear relationship between F/F0 and the concentration of calf thymus DNA covers 5.1 x 10(-6) - 2.41 x 10(-4) mol L(-1), which can be utilized for determining traces of calf thymus DNA with a detection limit of 1.1 x 10(-7) mol L(-1) in base pairs.
Liu
Guo-Dong
GD
Department of Chemistry, East China Normal University, Shanghai, P R China. guodongliu@263.net
Liao
Jian-Pei
JP
Fang
Yu-Zhi
YZ
Huang
Sha-Sheng
SS
Sheng
Guo-Li
GL
Yu
Ru-Qin
RQ
D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002417:Cattle; D002614:Chelating Agents / Q000032:analysis; D004247:DNA / Q000032:analysis*; D004996:Ethidium / Q000032:analysis; D005029:Ethylenediamines / Q000032:analysis*; D005030:Ethylenes / Q000032:analysis*; D005454:Fluorescence Polarization; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D009691:Nucleic Acid Denaturation; D011193:Potassium Iodide / Q000032:analysis; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors; D014001:Tin / Q000032:analysis*
D002614:Chelating Agents; D005029:Ethylenediamines; D005030:Ethylenes; D007202:Indicators and Reagents; D011193:Potassium Iodide; D014001:Tin; D004247:DNA; C427203:calf thymus DNA; C036216:ethylene; C011452:disalicylaldehyde ethylenediamine; D004996:Ethidium