RBCs lysate was mixed with anti–L-PK or anti–M1-PK antibody, followed by overnight incubation at 4°C. The mixture was then centrifuged, and the PK activity in the supernatant was measured. The antibody was diluted sequentially, and the effect of antibody treatment was evaluated at the most effective dilution. When PK activity dropped to 20% of original value after antibody treatment, the PK activity was considered to be abolished. When 70% of original PK activity was retained after antibody treatment, the treatment was considered to be of no effect. The experiments were repeated twice. Each RBC lysate for an assay was collected from the following numbers of mice: sample for day 1 or day 7 from 8 to 10 mice; sample for day 14 from 3 mice; sample for day 28, day 42, or day 90 from 2 mice.