Table 3.

Effects of Trypsin on Soluble and Microsomal PAL Activity and Microsomal C4H Activity in Extracts from Wild-Type Tobacco Plants

Total Activity (picokatals)a
Control0.1 % Triton X-1000.6 % Triton X-100
Soluble PAL392069606680
Microsomal PAL214211211
  • a Two grams of plant material was homogenized in 4 mL of extraction buffer and ultracentrifuged; the supernatant was assayed directly, and the pellet was resuspended in 250 μL of homogenization buffer. Fractions were incubated for 30 min at 4°C in the presence or absence of Triton X-100 before trypsin treatment (+Trypsin) or further incubation in the absence of trypsin (–Trypsin). Enzyme assays were started by the addition of substrate.