Analysis of the oxidative modification of proteins by means of fluorescence and elastic scattering

The fluorescence of pure tryptophan and tryptophan residues in albumin is studied at an excitation wavelength of 288 nm. The range of wavelength registration is 280–380 nm. A broad fluorescence band at 350–355 nm and an elastic scattering line at 288 nm are observed in the spectrum measured at 90° relative to the primary beam. The fluorescence of pure tryptophan and tryptophan in albumin is greatly reduced under the impact of the plasma radiation of a spark discharge, while the elastic scattering peak remains unchanged within the limits of error. A comparison of the elastic scattering and fluorescence indicates that tryptophan loses its inherent property to fluoresce under an external influence. The structure of the other tryptophan levels remains unchanged.