Purification and Characterization of Broad Bean Lipoxygenase Isoenzymes

• DOI: 10.1021/jf990463s
• Publication Date: 2002-07-26T05:57:48Z
• Authors: Alfonso Clemente; Raquel Olías; Jose Manuel Olías
• Keywords: Isoenzymes; Molecular Weight; Kinetics; 0303 health sciences; 03 medical and health sciences; Plants, Medicinal; Lipoxygenase; Chromatography, Gel; Fabaceae; Chromatography, DEAE-Cellulose; 6. Clean water

Two lipoxygenase isoenzymes, BBL-1 and BBL-2, were purified from broad beans. Fractionation of globulins and albumins by ionic strength was preferred to the classical water extraction system and the ammonium sulfate fractionation as initial purification steps. From the albumin fraction, BBL-1 and BBL-2 were purified 17.6 and 35. 7-fold, respectively, by conventional gel filtration and ion-exchange chromatography. The molecular weight of both BBL-1 and BBL-2 was 97 kDa with a maximal activity around pH 5.8; however, they showed a significant difference in their K(m) values for linoleic acid: 2.3 and 0.25 mM for BBL-1 and BBL-2, respectively. BBL-1 produced hydroperoxides and ketodienes while BBL-2 produced exclusively hydroperoxides.