Zinc tetra-4-(4'-carboxyphenoxy)phthalocyanine as a new site-specific marker for serum albumin

The interaction of zinc tetra-4-(4'-carboxyphenoxy)phthalocyanine with bovine serum albumin was studied via electron absorption spectroscopy and fluorescence spectroscopy. Being the associate in aqueous media, zinc tetra-4-(4'-carboxyphenoxy)phthalocyanine is converted to its monomeric form to be bound to albumin, with the monomeric form of the phthalocyanine being characterized by a fluorescence in the visible region of the spectrum. The displacement titration of albumin complexes with the known site-specific markers (such as warfarin, L-tryptophan, and hemin) and phthalocyanine was performed to show the location of zinc tetra-4-(4'-carboxyphenoxy)phthalocyanine within the IIA subdomain of albumin.