[Photochemiluminescence arising during sensitized photooxidation of trypsin solutions].

Kinetic study of eosin-sensitized photochemoluminescence (PCL) in tripsin solutions was carried out. Kinetics of luminescence increase and decrease, connection between sensitized PCL with triptophane photodissociation in protein were investigated. Effect of the concentrations of protein and oxygen in solution on the parameters of eosin-sensitized PCL was studied in order to establish the succession of processes resulting in the formation of free radicals. The experimental data made it possible to propose a scheme of primary processes responsible for PCL, which shows that the formation of protein radicals proceeded in the reactions between the triplet excited states of dye and singlet oxygen and protein triptophyle residues. It was found that during the formation of radicals in the air at small concentrations of proteins singlet oxygen played a major role in the sensitized photooxidation of protein. It was shown that the mechanism of processes responsible for sensitized PCL, determining postluminescence is similar to tripsin chemoluminescence under UV-illumination. Some kinetic parameters of the processes proceeding during sensitized photooxidation were determined and estimated.