Figure 2.
Activation of bovine glutamate dehydrogenase by digestion with untreated chymotrypsin. GDH (Mr = 55,561) (0.5 mg/mL) was incubated with 0.2 mg/mL chymotrypsin (Mr = 25,700), in 0.1 M phosphate buffer (pH 7.0) at 30°C. Dehydrogenase activity was periodically assayed (A) as described in Materials and Methods, utilizing NADP+ as the cofactor. Samples (50 uL) were also removed for treatment with PMSF before being loaded onto 12% SDS-PAGE gels. (B) Broad-range molecular weight markers (as in Fig. 1) were loaded in the first lane.