Katrahalli Umesha, Kalanur Shankara Sharanappa, Seetharamappa Jaladappagari
Department of Chemistry, Karnatak University, Dharwad 580 003, India.
Sci Pharm. 2010 Oct-Dec;78(4):869-80. doi: 10.3797/scipharm.1008-15. Epub 2010 Nov 6.
The binding of coomassie brilliant blue G (CBB) to bovine serum albumin (BSA) was investigated under simulative physiological conditions employing different optical spectroscopic techniques viz., fluorescence emission, UVâvisible absorption and FTIR. Fluorescence quenching data obtained at different temperatures suggested the presence of dynamic type of quenching mechanism. The binding constant of CBB-BSA and the number of binding sites (n) for CBB in BSA were calculated and found to be 4.20 Ã 10(4) M(â1) and 0.96 respectively, at 302 K. The value of n close to unity indicated that the protein has a single class of binding sites for CBB. The thermodynamic parameters revealed that the hydrophobic forces played a major role in the interaction of CBB to BSA. The distance between the CBB and protein was calculated using the theory of FÃsterâs Resonance Energy Transfer (FRET). The conformational change in the secondary structure of BSA upon interaction with dye was investigated by synchronous fluorescence and FTIR techniques. Competitive binding studies were also carried out to know the location of binding of CBB on BSA.
在模拟生理条件下，采用不同的光学光谱技术，即荧光发射、紫外 - 可见吸收和傅里叶变换红外光谱（FTIR），研究了考马斯亮蓝G（CBB）与牛血清白蛋白（BSA）的结合。在不同温度下获得的荧光猝灭数据表明存在动态类型的猝灭机制。计算了CBB - BSA的结合常数以及BSA中CBB的结合位点数（n），发现在302 K时分别为4.20×10⁴ M⁻¹和0.96。n值接近1表明该蛋白质对CBB有单一类别的结合位点。热力学参数表明疏水作用力在CBB与BSA的相互作用中起主要作用。利用福斯特共振能量转移（FRET）理论计算了CBB与蛋白质之间的距离。通过同步荧光和FTIR技术研究了BSA与染料相互作用时二级结构的构象变化。还进行了竞争性结合研究以了解CBB在BSA上的结合位置。
