Figure 6.

Immunodetection of carbonyl residues in 20S proteasomes from starved and non-starved maize root tips after oxidative treatment. Purified 20S proteasomes (2 μg) from T0 and T24-starved root tips were submitted to various oxidative treatments, incubated with DNPH, and separated by 12.5% (w/v) SDS-PAGE. Carbonyl residues were then immunodected with anti-DNP antibodies as described in “Materials and Methods.” Lanes 1 and 4, Nonoxidized 20S proteasomes from T0 and T24 starved root tips. Lane 2, 20S proteasome from T0 root tips treated for 2 h at 37°C with 50 mm ascorbate/200 μm FeSO₄. Lanes 3 and 5, 20S proteasome from T0 and T24 starved root tips treated for 2 h at 37°C with 50 mm ascorbate/200 μm FeSO₄/5 mm H₂O₂.