Figure 3. Cleavage of purified human component C3.

[A] Samples of purified human C3 (3 µg) were incubated with increasing concentrations of C-SVMP (0.01–0.32 µg) or PBS for 30 min at 37°C. Cleavage was visualized by SDS-PAGE under reducing conditions followed by silver staining. [B] C3 is formed by two protein chains, β and α (1,641 amino-acid residues). The arrow indicates the site of cleavage for C-SVMP and the amino acids determined by Edman degradation are underlined. Anaphylatoxin Domain (ANA).