[Transformation of free radicals of gamma-irradiated enzymes during long-term storage]. / Prevrashchenie svobodnykh radikalov v gamma-obluchennykh fermentakh pri dlitel'nom khranenii.

The ESR method was used to study free radical processes occurring in gamma-irradiated enzymes upon their long-term storage (up to 4 years) both at room temperature and at 4 degrees C. Simultaneously, studied was the biological activity of gamma-irradiated enzymes subjected to a long-term storage. The immobilization of enzymes on dialdehyde cellulose or polycaproamine was shown to preserve their biological activity during the postirradiation storage.

[The action of gamma irradiation on terrilytin immobilized on cellulose-fiber materials]. / Deistvie gamma-oblucheniia na terrilitin, immobilizovannyi na tselliuloznykh voloknistnykh materialakh.

The effect of gamma-radiation on terrilytin, a proteolytic enzyme immobilized on modified and nonmodified cellulose materials was studied by EPR. Dialdehyde cellulose and graft copolymer of cellulose and polyacrylic acid were used as the modified cellulose materials. Dependence of the native and immobilized terrilytin activity and the content of free radicals in the irradiated samples on the irradiation dose was observed. It was shown that immobilization of the enzyme led to increasing of its stability to the effect of the ionizing radiation. This was due to transfer of the free valency from terrilytin to the carrying polymer which prevented radiation and chemical destruction of the enzyme. The proteolytic activity of native terrilytin subjected to gamma-irradiation markedly decreased because of intramolecular and intermolecular interactions during reactions of the terrilytin free radicals, since in this case there was no polymer as an acceptor of the enzyme free valency.