Analysis Note

Protein determined by biuret.

Application

Lipoxidase from Glycine max (soybean) has been used for the modification of low density lipoprotein, isolated from human plasma.

The soybean enzyme will use arachidonic acid as a substrate, with ~ 15% of the activity indicated using linoleic acid as the substrate; the product of arachidonic acid oxidation is 12- or 15-hydroperoxyarachidonic acid (12-HPETE or 15-HPETE).

Biochem/physiol Actions

Catalyzes the hydroperoxidation of lipids containing a cis,cis-1,4-pentadiene structure.

Physical form

Suspension in 2.3 M (NH₄)₂SO₄ solution, pH approx. 6.0

Preparation Note

Prepared by ion exchange chromatography and hydrophobic interaction chromatography.

Unit Definition

One unit will cause an increase in A₂₃₄ of 0.001 per min at pH 9.0 at 25 °C when linoleic acid is the substrate in 3.0 ml volume (1 cm light path). One A₂₃₄ unit is equivalent to the oxidation of 0.12 µmole of linoleic acid.