ABSTRACT
The interaction atrazine and ct-DNA was studied using fluorescence probe and UV absorption spectroscopy technique. Ethidium bromide (EB) was used as a probe. The effects of atrazine, phosphate, concentration of ions, and potassium iodide on the fluorescence of ct-DNA-EB system were investigated. The results showed that the fluorescence quenching process of atrazine to ct-DNA-EB system was proved to be the simultaneous dynamic and static quenching model. The phenomena of fluorescence quenching of ct-DNA-atrazine system by KI and hyperchromicity and the red shift of DNA UV-absorption caused by atrazine indicated the existence of intercalation between atrazine and ct-DNA. The experiments of phosphate and ionic strength showed that atrazine could combine with the phosphate group of ct-DNA by non-characteristic static force, and this action could be inhibited by high ionic strength.
Subject(s)
Atrazine/chemistry , DNA/chemistry , Ethidium/chemistry , Indicators and Reagents/chemistry , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , Animals , Cattle , Fluorescent Dyes/chemistry , Hydrogen-Ion Concentration , Models, Chemical , Potassium Iodide/chemistryABSTRACT
The fluorescence spectra, absorption spectra and resonance light scattering (RLS) spectra of EGCG-Cu((II) complex with nucleic acid were studied. Compared with the spectrum of EGCG-Cu(II), the spectrum of EGCG-Cu(II)-DNA system showed the following features: (1) in the fluorescence spectra, the peak did not shift, but the fluorescence intensity was enhanced and was proportional to the concentration of DNA. Under suitable conditions, EGCG-Cu(II) promised to be a probe for detecting DNA; (2) Absorption spectra of EGCG-Cu(II)-DNA system showed hyperchromicity; and (3) RLS of EGCG-Cu(II)-DNA system was enhanced also. A mechanism was suggested that the combination of nucleic acid and EGCG-Cu(II) complex was caused by intercalation and electrostatic force. An intercalation interaction between EGCG-Cu(II) and DNA enhanced the fluorescence intensity. Hyperchromicity of absorption spectra and RLS occurred because of electrostatic force. The effects of acid and ionic strength on fluorescence intensity were also discussed.
