Figure 3.

Inhibition of PP1c activity by plant Inh3. A and B, Phosphatase activities were measured using [³²P]labeled myelin basic protein as a substrate in the presence or absence of the indicated concentrations of Inh3 protein. Phosphatase activities were expressed as percentages of the values of VfPP1c-1 (A) and TOPP4 (B) measured without inh3 protein. Error bars represent the means ± se (n = 3). The full activities correspond to 63,895 ± 1,889 and 70,078 ± 789 units/mg protein (± se, n = 3) for VfPP1c-1 and TOPP4, respectively. One unit represents the release of 1 nmol phosphate per minute at 30°C.