Abstract
In this study we examined the effect of temperature on self-degradation of a highly purified protease derived from kiwi fruit (Actinidia chinensis). The results obtained were as follows :
1) A protease was purified to homogeneity from kiwi fruit with a 42% activity yield.
2) Caseinolytic activity of purified protease increased linearly up to 20 min at 30°C.
3) The purified protease maintained nearly all of its caseinolytic activity after 30 min at 30-50°C, but the activity completely disappeared after 20 min at 70°C and after 3 min at 100°C.
4) The purified protease maintained not only peptide chain of itself but also its caseinolytic activity after 24 h at 30°C. On the other hand, after heating for 24 h at 50°C, the caseinolytic activity decreased to a level of 8% even though the peptide chain of itself had not degraded.
These results suggest that the protease purified from kiwi fruit has a high resistance against self-degradation by heat treatment.
