FIG. 1.

Inhibition of PP-1 and PP-2A activity by salivary P. papatasi gland lysates. Mφ cytosolic fraction (12.5 μg/ml) was incubated with different concentrations of salivary gland lysate for 15 min at room temperature, and PP activity was assayed by using [γ-³²P]ATP-labeled phosphorylase A as the substrate. Inset, PP activity from the cytosolic fraction of C3H/HeN mice Mφ as a function of Mφ-derived protein (1 mU = 1 nmol of phosphate released from phosphorylase A/min/ml).