Figure 2.

GIIβ is not necessary for GIIα activity toward pNPG. GII activity was measured in total cell extracts and in microsomal fractions. We incubated 125 μg of either total S. pombe cell extract (A) or microsomal proteins (B) of wild-type, ΔGIIα, or ΔGIIβ S. pombe cells with 5 mM pNPG for 20 min at 37°C. The reactions were stopped with 20 μl of 10% SDS and 50 μl of 2 M Tris base. Absorbance was measured at 405 nm.