Lipoxygenase carotene oxidase

Considerable purification of lipoxygenase from soybeans was achieved by Balls et al (15), They used conventional protein purification methods and the carotene oxidase reaction to follow the enzyme activity. Theorell et al, (16), in 1947, crystallized the enzyme, or more correctly, one of the several isoenzymes in soybean. We believe this was lipoxygenase-1 as described later. 

Isoenzymes. Kies (90), who questioned the identity of lipoxygenase and carotene oxidase, thought that the lipoxygenase activity of soybeans was caused by more than one enzyme. She discovered that a partially... 

Enzymes of this type were formerly known as fat oxidase, carotene oxidase, and lipoxidase lipoxydase in French) and have also been listed under E.C. 1.99.2.1 and E.C. 1.13.1.13. It should be emphasized that several species of enzyme, distinguishable by substrate and product specificities as well as by physical properties, are covered by the generic term lipoxygenase. ... 

Lipoxygenases from different sources differ in their cooxidation activity. Enzymes from peas and beans (Phaseolus sp.) and the LOX-2 from soybean have a high cooxidation potential potato LOX is intermediate, whereas wheat, flax, and soybean LOX-1 have poor cooxidation activity (Grosch et al., 1976, 1977). Thus, the carotene oxidase activity of soybeans is associated with the LOX-2 isoenzyme, and this explains the observed selective loss of carotenoid bleaching activity during the purification and heat treatment of the classic (i.e., LOX-1) enzyme from soybean (Kies et al., 1969). 

The presence of a lipid-oxidizing enzyme in plants, then termed lipoxidase, was first described by Andre and Hou in 1932 [1]. A pigment bleaching property, attributed to a separate enzyme activity described as carotene oxidase, was later found to originate from this enzyme as well [2]. The name lipoxygenase (linoleateioxygen oxidoreductase, EC 1.13.11.12) is now used for this enzyme. 

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