Absorption, Fluorescence and Resonance Rayleigh Scattering Spectra of Interaction of Papain with Calf Thymus DNA  

作　　者：孔玲 刘忠芳 胡小莉 刘绍璞 

机构地区：[1]Luminescence and Real-Time Analysis, Key Laboratory of Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China

出　　处：《Chinese Journal of Chemistry》2011年第4期822-828,共7页中国化学（英文版）

基　　金：Project supported by the National Natural Science Foundation of China （No. 20875078）, the Youth Fund of Southwest University （No. 20710403） and Open Foundation of Large Instruments of Southwest University （No. 201005）.

摘　　要：In weak acidic medium, interaction between papain and calf thymus DNA （ctDNA） resulted in absorption spectral change, fluorescence quenching of papain and remarkable enhancement of resonance Rayleigh scattering （RRS） The interaction types and binding modes were discussed by characteristics of RRS, absorption, fluorescence and circular dichroism spectra combining thermodynamic data. Four interaction types include electrostatic attraction, hydrophobic force, hydrogen bonding and aromatic stacking interaction. Papain interacted with the major groove of ctDNA. Aromatic stacking interaction is the main reason of change of absorption spectrum and fluorescence quenching of papain. Surface enhanced scattering effect, resonance energy transfer effect, increase of molecular volume and conformational change make contribution to RRS enhancement. The enhanced RRS intensity （△I） is directly proportional to the concentration of ctDNA or papain, The detection limit （3σ） is 5.2 ng·omL^-1 for ctDNA and 5.6 ng·mL-1 for papain. This creates conditions for determination of papain and ctDNA.In weak acidic medium, interaction between papain and calf thymus DNA （ctDNA） resulted in absorption spectral change, fluorescence quenching of papain and remarkable enhancement of resonance Rayleigh scattering （RRS） The interaction types and binding modes were discussed by characteristics of RRS, absorption, fluorescence and circular dichroism spectra combining thermodynamic data. Four interaction types include electrostatic attraction, hydrophobic force, hydrogen bonding and aromatic stacking interaction. Papain interacted with the major groove of ctDNA. Aromatic stacking interaction is the main reason of change of absorption spectrum and fluorescence quenching of papain. Surface enhanced scattering effect, resonance energy transfer effect, increase of molecular volume and conformational change make contribution to RRS enhancement. The enhanced RRS intensity （△I） is directly proportional to the concentration of ctDNA or papain, The detection limit （3σ） is 5.2 ng·omL^-1 for ctDNA and 5.6 ng·mL-1 for papain. This creates conditions for determination of papain and ctDNA.

关 键 词：PAPAIN calf thymus DNA absorption spectrum fluorescence spectrum resonance Rayleigh scattering 

分 类 号：O657.3[理学—分析化学] TB383[理学—化学]