论文部分内容阅读
采用紫外吸收光谱和荧光光谱研究了菁染料MTC超分子聚集体与人血清白蛋白(HSA)之间的相互作用。研究表明在p H=7.4的Tris-HCl缓冲溶液中,MTC主要以J-聚集体的形式存在而非单体。当HSA存在时,J-聚集体部分分解转变为H-聚集体。同时,MTC对HSA的内源荧光有较强猝灭作用,猝灭机制属于生成复合物的静态猝灭,二者结合常数为6.86×105M-1,结合位点数为1。MTC的存在导致了色氨酸所处微环境极性增大,疏水性降低,肽链变得更加伸展。
The interaction between the cyanine dye MTC supramolecular aggregates and human serum albumin (HSA) was studied by UV absorption spectroscopy and fluorescence spectroscopy. Studies have shown that in Tris-HCl buffer solutions with pH 7.4, MTC is predominantly in the form of J-aggregates rather than monomers. J-aggregates partially decompose into H-aggregates when HSA is present. At the same time, MTC quenched the endogenous fluorescence of HSA strongly, and the quenching mechanism belongs to the static quenching of the resulting complex, with a binding constant of 6.86 × 10 5 M -1 and a binding site of 1. The presence of MTC results in the increase of the polarity of tryptophan in the microenvironment, the decrease of hydrophobicity, and the extension of the peptide chain.