FIGURE 3.

Degradation of casein by AMZ-tk and self-cleavage activity of purified AMZ-tk analyzed by SDS-PAGE. (A) Degradation of casein by AMZ-tk. Purified AMZ-tk was incubated with casein at 55°C in the presence of 0.08 mM divalent ions or 5 mM EDTA for 30 min. Casein alone was used as control. Samples were analyzed using 12% SDS-PAGE and Coomassie Brilliant Blue staining. (B) Self-cleavage of purified AMZ-tk. Purified AMZ-tk was incubated at 55°C in the presence of 0.08 mM divalent ions or 5 mM EDTA for 30 min. Fresh purified protein was used as control. Samples were analyzed using 12% SDS-PAGE and Coomassie Brilliant Blue staining. The upper panel shows the density of protein bands. ^∗p < 0.05 compared with fresh purified protein.