Properties of the catalase molecule obtained from acatalasemic and hypocatalasemic mice Part I. Effects of denaturants on the catalase activity in the mouse liver

Homogenates of mouse liver with isotonic sucrose solution were separated by the cell fractionation with repeating centrifugation. The supernatants were used for the inhibition test with the reagents such as 3,5 diiodosalicylic acid lithium salt (LIS), guanidine and azide, heat, acid and alkali. After various treatments, the remaining catalase activities were measured and showed as a relative enzyme activity. Stability of catalase in liver supernatants was compared normal (C3H/C(as)C(as)) and mutant mice which were designated acatalasemia (C3H/C(bs)C(bs)), hypocatalasemia (C3H/C(cs)C(cs)) and acatalasemic heterozygote (C3H/C(as)C(bs)). In both treatments of LIS and guanidine, catalase of C(as)C(as) was most stable, C(bs)C(bs) were unstable, and catalase of C(cs)C(cs) and C(as)C(bs) showed midle stability between the stability of C(as)C(as) and C(bs)C(bs) in this order. On the contrary in azide treatment within the range from O to 1mM azide, C(bs)C(bs) was most stable, and C(as)C(as), C(cs)C(cs) and C(as)C(bs) were unstable in this order, but more than 1mM azide, C(cs)C(cs), C(as)C(as) and C(as)C(bs) were unstable in this order. After incubation at various temperatures changing from 30℃ to 60℃ for 10min, C(as)C(as) was most stable, and C(as)C(bs), C(cs)C(cs) and C(bs)C(bs) were unstable in this order. After acid and alkali treatments in the range of pH 5.5 to 9.0, relative activities of C(cs)C(cs) and C(as)C(bs) were similar to that of C(as)C(as), but C(bs)C(bs) was less stable than C(as)C(as), C(cs)C(cs) and C(as)C(bs) in the same range. It is considered that the structure of catalase molecule in the liver is different between normal, mutant mice and heterozigote of normal and mutant mice with regard to the difference of the stability to LIS, guanidine, azide, heat, acid and alkali treatments.