孔雀石绿与牛血清白蛋白作用的光谱研究

Study on the spectral characteristics of the interactions between malachite green and bovine serum albumin

应用荧光及紫外光谱法研究了孔雀石绿(MG)与牛血清白蛋白(BSA)相互作用的光谱特性。测定了16℃、26℃、36℃三个温度下的结合常数KA(7.066×103、4.638×103、1.338×103)和结合位点数n(1.2、1.1、1.0)。结果表明:MG对BSA内源荧光的猝灭机理主要为静态猝灭;MG主要以范德华力与BSA相互作用;同步荧光技术研究了MG对BSA构象的影响,表明BSA的荧光主要源于色氨酸残基,MG对BSA的构象有影响;利用F ster偶极-偶极非辐射能量转移理论,计算了三个温度下MG与BSA的作用距离(r16℃=3.30,r26℃=3.314,r36℃=3.58nm),表明MG对BSA的荧光猝灭中存在能量转移。

The interactions between malachite green and bovine serum albumin （BSA） were studied by fluorescence and ultravioletvisible absorption spectrum The binding constants KA （ 16℃ ：7.066×10^3 ,26℃ ：4. 638 × 10^3 ,36℃ ： 1. 338× 10^3 ） and binding sites n（ 16℃ ：1.2,26℃ ： 1.1,36℃ ： 1.0） were measured at different temperatures. The experimental results revealed that malachite green has strong ability to quench the intrinsic fluorescence of BSA and the interactions has been verified as consistent with the static quenching procedure. According thermodynamic parameters the acting forces were determined to be Vanderwaals force. Based on the mechanism of the Foester energy transference, the transfer efficiency of energy E and transfer distance r between acceptor malachite green and donor BSA were obtained at different temperatures. E =0. 112（ 16℃ ） ,E =0. 105 （26℃） ,E =0. 059 （36℃）, r =3.30（ 16℃ ） ,r =3. 314（26℃ ） ,r =3.58nm（36℃ ）.