Studies on the effect of irradiation to the protein

Solid gelatin irradiated with gamma-rays of 60Co showed changes in the formation of cross-links in protein hydrogel as reported in our previous paper. After adding Cu++ and Fe++ ions we observed recovery from these changes which had been caused by irradiation. Heat energy from the formation of cross-links in the irradiated protein was calculated from the values of the melting and setting points of hydrogels in the presence or absence of Cu++ and Fe++ ions. The decrease in heat energy from the cross-linking process caused by irradiation was restored to a certain extent with an addition of these metal ions. The relative heat of reaction for ΔH sub(m-s) sup(0) was estimated to be greater than that for ΔH sub(s) sup(0). The results suggest that injured crosslinking loci in the irradiated protein molecule could be recovered with the metal ions to a certain extent the degree of which may be greater in the cross-linking process II than that in the cross-linking process I. (auth.)