Lipoxygenase from Ulva lactuca [Ubvales, chloropyta]

ABSTRACT

Lipoxygenase enzyme [linoleate oxygen oxidoreductase EC 1.99.2.1] was separated and purified from the green alga Ulvalactuca by extraction of the cell-free extract, precipitation with 45% to 70% solid ammonium sulfate and chromatography on DEAE Sephadex A 50. This preparation has given two bands [Lipoxygenase 1 and 2] by disc gel electrophoresis. Lipoxygenase enzyme from Ulva has been obtained in 60% yield with specific activity in the range of 1262 n mol, hydroperoxylinoleate mg[-1]protein. A purification 63-fold was achieved from Ulva. The optimum pH of Ulva lipoxygenase is 8.0. The molecular weights of lipoxygenase 1 and 2 were 120000 and 103000 respectively. K[m]and V [max] were 307.6 uM and 250 n mol per mg protein ml[-1]min[-1] respectively. No unusual amino acids were detected by the amino acid analyser. There is no cystine in Ulva lipoxygenase. The iron content of the purified lipoxygenase enzyme was 1.05 ppm