光谱探针猩红S与牛血清白蛋白结合的发光光谱

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Fo...

Luminescence Spectroscopy of Conjugation Reaction between Bovine Serum Albumin and Spectroscopic Probe Ponceau S

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).