Fig 4.

Cleavage of IgM but not IgG and IgA by recombinant Ide_Ssuis constructs. (A) Illustration of rIde_Ssuis and its truncated derivatives. Regions similar to IdeS of S. pyogenes are shaded. (B) Anti-His Western blot analysis of purified rIde_Ssuis (a) and its truncated derivatives (b to d) illustrated in panel A. (C) Anti-IgM Western blot (PAB) of diluted porcine plasma incubated with 5 μg/ml of rIde_Ssuis (a) or its truncated derivatives (b to d) illustrated in panel A. (D) Anti-IgM Western blot analysis (PAB) of diluted porcine plasma incubated with increasing concentrations of rIde_Ssuis as indicated or with PBS for 10 min at 37°C. (E, F) Anti-porcine (E) and anti-human (F) IgG Western blot analysis of diluted porcine and human plasma, respectively, incubated with 5 μg/ml of rIde_Ssuis (a) or its truncated derivatives (b to d) shown in panel A. Recombinant IdeS of S. pyogenes was included as positive control for cleavage of human IgG. (G) Anti-porcine IgA Western blot analysis of diluted porcine plasma incubated with 5 μg/ml rIde_Ssuis (a) or its truncated derivatives (b to d) illustrated in panel A. The final dilution of porcine plasma was 1:100 in all samples. The marker bands are shown on the left (sizes in kDa).