Purification and Characterization of Lipoxygenase from Glycine max (L.) Merr. (Black Soybean)

Abstract

The lipoxygenase (LOX, EC 1.13.11.12) from Glycine max (L.)Merr.(black soybean) was purified 71.4-fold and characterized. The molecular weight of LOX from G. max (L.) Merr.was 92.1 kDa and it is a dimer with subunits with molecular weight of 52.5 and 46.5 kDa. The optimum pH and temperature of black soybean LOX from black soybean was pH 9.5 and 35°C, respectively. The LOX was stable between pH 6.0 to 10.0 and below 40°C, respectively. The LOX showed the best preference in order to linoleic acid to α-linolenic acid, DHA, γ-linolenic acid, EPA, and oleic acid. When LOX from G. max (L.)Merr.reacted with linoleic acid, the main product was 13-hydroperoxy-9,11-octadecadienoic acid (13-HPOD). The best substrate, linoleic acid, was used to determine the kinetic parameter of the LOX and the Km, Vmax, and kcat values were 192.1μM, 98.0μmol_x0001_min-1, and 65.3 min-1, respectively. Finally, the characteristics of LOX from G. max (L.) Merr.determined in this research would be contributed to understanding of soybean LOX and utilized to find LOX inhibitor to regulate the LOX.