Proteolytic activity of C-SVMP on human purified Complement components.

The C-components, C3, C4 and C5 (3 µg) were incubated with increasing concentrations of C-SVMP (0.01 µg–0.32 µg). Cleavage of C-components was visualized by SDS-PAGE (10%) under reducing conditions followed by silver staining. The percentage cleavage of the α chain (C3, C4 and C5) was quantified by densitometry [A–C]. Purified human complement proteins C3, C4 and C5 (3 µg) were also incubated with purified C-SVMP (0.5 µg) or Bothrops venom (1 µg) in the presence or absence of 1,10 phenanthroline (Phe - 15 mM), a metalloproteinase inhibitor [D–F]. Generation of anaphylatoxins, after treatment of C3, C4 or C5 samples (3 µg) with C-SVMP (0.5 µg) or Bothrops venom (1 µg), was determined by ELISA [G–I]. Data are representative of three separate experiments. **p<0.01; ***p<0.001.