Figure 5.

Effects of H₂O₂ exposure on D. labrax and C. hamatus 26S proteasomes. (A) Native-PAGE analysis of 26S proteasomes, after incubation with increasing H₂O₂ concentrations for 24 h at 37 °C, is shown in comparison with that performed on the T. bernacchii 26S proteasome reported in Gogliettino et al. [18]. The arrow indicates the position of 26S proteasome band in each lane. The bands were visualized by Coomassie blue staining. (B) Densitometric analysis of Native-PAGE bands were performed by CHEMIDOC XRS and QUANTITY ONE software and expressed as percentage density of the 26S proteasome gel band at all the H₂O₂ concentrations tested. The experiments were performed in duplicate on two different protein preparations loading equal amounts of 26S proteasomes. Densitometric data are expressed as means ± standard deviations. (C) CT-like 26S proteasome activities after incubation at the indicated H₂O₂ concentrations for 24 h. Data were expressed as % of 26S activity inhibition.