The concentration of catalase protein in anemic blood with enhanced population of reticulocytes and in non-anemic blood was determined immunologically by double diffusion test with anti-mome-liver catalase rabbit serum. The change in catalase protein concentration in anemic blood during incubation at 37°C for 24 hours was also studied. It was indicated that the diminished catalase activity in acatalasemic blood was due to the depletion of the protein and that catalase protein in acatalasemic reticulocytes decreased markedly by in vitro maturation. Furthermore, the possible presence of inactive catalase protein in acatalasemic blood was also suggested. Catalase protein concentration of acatalasemic anemic blood
decreased by the incubation at 37°C for 24 hours in parallel with the decrease in reticulocyte count and catalase activity, and the decrease in catalase protein concentration of hemolysate by the same incubation parallel with the decrease in catalase activity. It is hypothesized that the unstable catalase protein with genetical change in structure easily decomposes during acatalasemic reticulocyte maturation is presented.</p
