Call Prefix : PR-T

Call Suffix : 1980

Call Cutter : D - FoSc 1

Location : SEARCA Library

Format : TD

Publisher : University of the Philippines Los Baños,

Publication Date : May 1980

Publication Place : Los Baños, Laguna, the Philippines :

Summary : ypoxygenase (linoleate: oxygen oxidoreductase E. C. 1.13.11.12) in winged bean and cowpea seeds were studied using various spectrophotometric assay, isolation and purification procedures. Winged bean lipoxygenase specific activity was comparable to that of soybeans while cowpea's is about 10 times that of soybeans and winged beans. Winged bean has high protein and fat contents which are similar to soybeans, ranging from 30 to 38.5 percent and 16.9 to 20.5 percent, respectively. Lipoxygenase activity and fat content decreased during seed germination. The fatty acid composition of five native winged bean lines determined by GLC was similar to peanut oil. The major unsaturated fatty acids were oleic and linoleic acid. Linoleic acid values ranged from 21 to 36 percent of the oil by both GLC and enzymatic methods. However, linoleic acid and parinaric acid were not present in the samples analyzed. Winged bean and cowpea lipoxygenase activities were located in 30-50 percent and 40-60 percent (NH4) (subscript 2) SO (subscript 4) precipitates, respectively. Disc gel electrophoresis followed by specific enzyme staining revealed 5 and 4 isoenzymes for winged bean and cowpea lipoxygenase with a major isoenzyme at Rf = 0.21 - 0.27. Purification of winged bean lipoxygenase on CM-Sephadex column had a poorer performance compared to DEAE-Sephadex column. A purification procedure of winged bean lipoxygenase using (NH4) (subscript 2) SO (subscript 4) fractionation and sequential Sephadex G-150, DEAE-Sephadex and hydroxyapatite chromatography revealed two major isoenzymes, F1 and FII, with 104 and 171-fold purification, respectively, compared to the crude extract.