RT Journal Article
SR Electronic
A1 Vanko, M.
A1 Rauová, D.
A1 Bezáková, L.
A1 Holková, I.
A1 Bilka, F.
A1 Cupáková, M.
T1 Biochemical properties of lipoxygenase from opium poppy chloroplasts
JF Biologia plantarum
YR 2012
VO 56
IS 1
SP 105
OP 110
DO 10.1007/s10535-012-0023-4
UL https://bp.ueb.cas.cz/artkey/bpl-201201-0016.php
AB Lipoxygenase (LOX) from opium poppy (Papaver somniferum L.) chloroplasts was isolated and 126.1-fold purified to electrophoretic homogeneity by combination of ion-exchange chromatography on HA-Ultragel column and affinity chromatography on a linoleyl-aminopropyl agarose column. The relative molecular mass of the LOX determined by SDS-PAGE was 92 kDa. Kinetic properties of purified LOX were determined in spectrophotometric assay by using of linoleic acid (K<sub>M</sub> = 1.78 mM and V<sub>max</sub> = 11.4 μmol mg<sup>-1</sup> min<sup>-1</sup>) and linolenic acid (K<sub>M</sub> = 1.27 mM and V<sub>max</sub> = 10.2 μmol mg<sup>-1</sup> min<sup>-1</sup>). The optimum pH was 6.0 for both linoleic and linolenic acid dioxygenation catalyzed by LOX. HPLC analysis of the products revealed a dual positional specificity of linoleic acid dioxygenation at pH 6.0 with ratio of 9- and 13-hydroperoxide products being about 1:1. The activity of purified LOX was stimulated by Mg<sup>2+</sup> and Ca<sup>2+</sup>.