光谱分析法研究八羧酸酞菁铝配合物与牛血清白蛋白的结合作用

以八羧酸酞菁铝配合物(AlPc(COOH)8)为红区荧光探针,用紫外光谱和荧光光谱分析方法研究了(AlPc(COOH)8)与牛血清白蛋白(BSA)的结合作用,测定了八羧酸酞菁铝与牛血清白蛋白(BSA)的结合位置数和结合常数,结果分别为n=5.7,K=5.74×105和K=3.51×105,两种分析方法结果基本一致.以氯血红素(HE)、布洛芬(IB)、L-色氨酸(TRP)为分子探针,用络合竞争法研究了它们对AlPc(COOH)8-BSA体系紫外光谱的影响,结果表明,往体系中加入HE后,AlPc(COOH)8的单体吸收峰增强,体系由结合态往游离态"转变",而加入TRP和IB后,吸收光谱未观察到明显的变化,由此确定AlPc(COOH)8与BSA的结合点为SiteⅠ.

Synthesis and Characterization of Octa-Carboxylic Phthalocyanine Aluminum and Its Interaction with Bovine Serum Albumin

Octa-carboxylic phthalocyanine aluminium (AlPc(COOH)8) was used as fluorescent probe of infrared region. The interaction of octa-carboxylic phthalocyanine aluminium (AlPc(COOH)s) and bovine serum albumin(BSA) was studied by UV/ Vis and fluorescence spectra methods. The binding constant KA and n of phthalocyanine aluminium with BSA were determined. The results were K=5. 74 X 10(5) , n= 5. 7 and K= 3. 51 X 10(5) , for these two methods respectively. The same results by using two different analytical methods were obtained. Besides, hemin chloride(HE), ibuprofen(IB) and L-tryptophan(TRP) were used as probes, and the effects of these probes on the spectra of AlPc(COOH)8 )-BSA were studied by competitive binding method. The result indicated that, by adding HE into the AlPc(COOH)8)-BSA system, obvious spectral change of the system was observed, while adding TRP and IB caused no spectral changes. The binding site of octa-carboxylic phthalocyanine aluminium on the BSA was found to be at the I site by competitive binding method.