Figure 7. Activity of EndoS₂ on native and denatured IgG and AGP, other glycoproteins and chitinase assay.

(A) IgG was incubated at temperatures ranging from 37 to 80°C for 30 min followed by incubation with EndoS₂ at 37°C for 2 h and analysis by SDS/PAGE and LCA lectin blot. (B) AGP was incubated at 37–70°C followed by incubation with EndoS₂ at 37°C for 2 h and analysis by SDS/PAGE. (C) EndoS₂ was incubated with α₂-macroglobulin, ovalbumin, human lactoferrin, RNase B and fetuin at 37°C overnight and analysed by SDS/PAGE. (D) EndoS₂, EndoS and a chitinase from S. griseus was incubated with the fluorescent substrate 4MU-GlcNAc for 1 h and fluorescence was measured at 355/445 nm. The experiments were carried out using five replicates and results are means±S.D. The response in absorbance was analysed statistically by an unpaired Student's t test, where differences was considered significant if P<0.05. ****P<0.001.