Genetic regulation of the expression of catalase activity in murine red blood cells.

The specific activity (k'1) and concentration of red blood cell catalase from four inbred strains of mice (BALB/c, C57BL, C57BL/6, and NBL) were measured to determine the mechanisms responsible for interstrain variations in enzyme activity. The specific activities of RBC catalase in NBL and the C57BL sublines are equal (2.5 x 10(7) M-1 sec-1), while that of BALB/c (4.0 x 10(7) M-1 sec-1) is 67% greater. The relative concentration of catalase is approximately 30% lower in NBL erythrocytes compared to the other three strains. The activity of BALB/c RBC catalase is due to a high k'1 coupled with a high intracellular concentration; RBC catalase activity in the C57BL sublines is the result of a low k'1 and high concentration. A low k'1 and a low concentration are responsible for the low catalase activity levels found in NBL erythrocytes.