[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.