Effect of SpeB and EndoS from Streptococcus pyogenes on human immunoglobulins

Streptococcus pyogenes secretes a specific immunoglobulin G (IgG)-protease, Spell, as well as the IgG glycan-hydrolyzing enzyme EndoS. Here we show th at SpeB also degrades IgA, IgM, IgD, and IgE. We also show that EndoS only hydrolyzes the glycan moiety on native but not denatured IgG. Thus, Spell h as a broad immunoglobulin-degrading activity, while EndoS is highly specifi c for IgG.