Purification and characterization of lipoxygenase from aromatic and non-aromatic rice (Oryza sativa L.)

Lipoxygenase (Lox) has been extensively purified from aromatic (Bas-370) and non-aromatic (Pusa-834) rice varieties. Crude isolates of Lox from the aromatic varieties (Bas-370 and PB-1) showed higher specific activity (4-fold) when compared to non-aromatic varieties (Pusa-677 and Pusa-834). The activity was optimum at pH 8.0 in all four varieties. Anionic PAGE of Lox from three days old seedlings revealed one extra band (Rm 0.48) in aromatic varieties, besides the presence of a major band (Rm 0.28) in all the four varieties. Elution profile of Lox from Bas-370 and Pusa-834 on DEAE-cellulose column showed three distinct peaks (L-1, L-2 and L-3), L-2 being the major fraction in both the varieties. SDS-PAGE of purified L-2 from Bas-370 showed a single band of molecular mass -88 kDa.