Time-dependent inhibition of TPP I by the prosegment as a function of
prosegment concentration. A, TPP I at 0.5 nm was
incubated with substrate at 100 μm and at the indicated varying
concentrations of prosegment in 100 μl of total volume of 50 mm
sodium acetate, pH 5.0, on a 96-well microtiter plate, and AMC fluorescence
was acquired continuously with intermittent shaking. All data points are the
average of quadruplicate measurements. Only every 10th data point collected is
shown for clarity. B, the calculated kobs rates
from A were replotted as a function of prosegment concentration.