Spectroscopic Properties of Protein Chromophores

Abstract

The protein molecule, with respect to its spectroscopic properties, may be considered as a complex system of chromophore groups which differ in structure and position of spectra. The protein absorption spectrum is at first approximation, the superposition of spectra of chromophores composing the protein molecule. The most extensive research effort has been focused on the 190–220 nm spectral range in which the peptide group absorption and the absorption of many amino acid residues are observed, as well as on the range of approx. 280 nm in which tyrosine and tryptophan absorption occurs. Both ranges are used for conducting experiments in protein spectroscopy. In emission spectra the contribution of the tryptophan chromophore is the most important one. A detailed description of spectroscopic properties of chromophores composing the protein molecule and their analogs is given below.