CAJ | 학술논문

利用荧光光谱和紫外吸收光谱,详细研究了不同温度下猩红S(PS)与牛血清白蛋白(BSA)的结合反应,发现PS对BSA的内源性荧光具有较强的猝灭作用,其猝灭机理属于静态猝灭,由此求得PS与BSA间的结合常数、结合位点数及热力学参数等.结果表明:PS与BSA之间形成了1:1稳定复合物,它们之间的作用力主要是静电引力.根据Forster非辐射能量转移理论,确定了PS与BSA之间的结合距离r<7 nm.同步荧光光谱研究表明:PS对BSA构象发生了影响,使BSA酪氨酸残基所处环境的极性减弱疏水性增强而色氨酸残基不受影响.利用对血清蛋白具有特异性结合的竞争试剂确定了PS在BSA的键合位点为ⅡA亚区的site I,证明PS与BSA也存在特异性结合,PS可以用作新的位置探针替代竞争试剂来研究小分子与蛋白的结合位置.
이용형광광보화자외흡수광보,상세연구료불동온도하성홍S(PS)여우혈청백단백(BSA)적결합반응,발현PS대BSA적내원성형광구유교강적졸멸작용,기졸멸궤리속우정태졸멸,유차구득PS여BSA간적결합상수、결합위점수급열역학삼수등.결과표명:PS여BSA지간형성료1:1은정복합물,타문지간적작용력주요시정전인력.근거Forster비복사능량전이이론,학정료PS여BSA지간적결합거리r<7 nm.동보형광광보연구표명:PS대BSA구상발생료영향,사BSA락안산잔기소처배경적겁성감약소수성증강이색안산잔기불수영향.이용대혈청단백구유특이성결합적경쟁시제학정료PS재BSA적건합위점위ⅡA아구적site I,증명PS여BSA야존재특이성결합,PS가이용작신적위치탐침체대경쟁시제래연구소분자여단백적결합위치.
Ponceau S (PS) can quench the fluorescence of bovine serum albumin (BSA) in the aqueous solution of pH = 7.40. The static fluorescence quenching process between BSA and PS was confirmed and the binding constant,the number of binding sites and thermodynamic parameters between BSA and PS were obtained. It showed that the number of binding sites was 1 and the electrostatic attraction played an important role in the binding of BSA to PS.Based on the theory of Forester energy transfer, the binding distance (r<7.0 nm) between PS and BSA was ob-tained. Studies utilizing synchronous spectra showed that the conjugation reaction between PS and BSA would affect the conformation of BSA, leading to the weak polarity around tyrosine residues and the strong hydrophobicity. The site markers competitive experiments indicated that the binding of PS to BSA primarily took place in sub-domain ⅡA (site I).