Spectral features of films of bovine serum albumin with thiochrome

Abstract

Optical absorption spectra and Raman scattering are studied for films of BSA, thiochrome and their composite. It is shown that the absorption spectra are rearranged in the composites compared to films of pure BSA and tiochrome. Quantum-chemical calculations for vibrations indicate that the reason for the rearrangement of the optical spectra is the π-staking interaction between the molecules of thiochrome and tryptophan of BSA. The results show that tiochrome dye with π-conjugated structure is a sufficient natural sensor that allows detection of tryptophan peculiarities in proteins.