Strict criteria prove that the catalase activity is intrinsic properties of scz-IgGmix and health-IgGmix.

Preparations of scz-IgGmix (A) and healthy-IgGmix (B) were separated by FPLC gel filtration on a Superdex 200 column in an acidic buffer Gly-HCl pH 2.6 after Abs incubation in the same buffer: (—), absorbance at 280 nm (A280); (○), relative activity (RA) of the IgGmix in the degradation of H2O2. Analysis of the thermal stability of scz-IgGmix; the preparation was preincubated at various temperatures for 10 minutes and then its relative catalytic activity was estimated using standard conditions (C). SDS-PAGE analysis of catalase activity of intact scz-IgGmix (D) as well as separated H, L chains and their LnHn oligomers (F) in non-reducing SDS-PAGE gradient 4–15% scz-IgGmix before (D) and after treatment of IgGs with DTT (F); panel F corresponds to lane 2 of Panel E. The relative catalase activity (RA, A240/min) was revealed using the extracts of 2-3-mm many fragments of one longitudinal slice of the gel corresponding IgGs before (D) and after treatment with DTT (F). The control longitudinal slices of the same gels were stained with Coomassie R250 (E): lane 1 corresponds to intact IgGmix, lane 2 to IgGmix incubated with 40 mM DTT for 10 min at 30°C, lane 3 to IgGmix boiled with DTT. Lane C (E) shows the positions of molecular mass standard markers. The relative activity of F(ab) and F(ab)2 fragments of individual IgG(4), IgG(12), and IgG(14) (G). The average error of the initial rate determination from two experiments did not exceed 10–15%. For details, see Materials and methods.