Fig 5.
SDS-PAGE analysis of Prc proteolytic activity on β-casein, IgG, C1q, or C3b. Proteolysis assays were performed by using the C-terminally His6-tagged Prc protease with β-casein, IgG, C1q, or C3b as the substrate. Reaction mixtures were incubated at 37°C for 2.5 h and subjected to SDS-PAGE analysis. The molecular masses of β-casein and the recombinant Prc protease are 25.3 kDa and 75.2 kDa, respectively. Note that IgG contains light (25 kDa) and heavy (55 kDa) chains. C1q contains A (26 kDa), B (25 kDa), and C (24 kDa) chains. C3b contains α (101 kDa) and β (75 kDa) chains.