Identification of different classes of superoxide dismutase in carnation petals.

Isoelectric focusing and nondenaturing two-dimensional electrophoresis, followed by an enzymatic characterization involving use of specific inhibitors were applied to identify the different forms of the superoxide dismutase (SOD) extracted from petals of cut carnation. Electrophoresis was carried out either with the crude extract or with fractions obtained after ion exchange chromatography of the extract. Three forms of the SOD were identified (Cu,Zn-SOD, Fe-SOD and Mn-SOD). They have close pI's (4.7 to 4.9) and most of them are composed of several isoforms.