Abstract

Lipase or triacylglycerol acylhydrolase (E.C.3.1.1.3) was purified to homogeneity from rapeseed-germinated cotyledons (Brassica napus L.). The purification scheme involved homogenization, centrifugation, ultracentrifugation and affinity chromatography using polyclonal antibodies raised against porcine pancreatic lipase. The purified rapeseed lipase was homogenous and did not contain contaminating proteins detectable by SDS-PAGE and HPLC analysis. The specific activity of the purified preparation was increased about 1950 times, with an overall yield of 35%. The rapeseed lipase was found to be a cytosoluble, glycosylated and heat-labile serine-hydrolase. It was monomeric with a molecular mass of 38 kDa and a pI of 6.6. The purification method used in the present work is rapid, simple and yields highly purified lipase. It may therefore be applicable in the purification of other uncharacterized plant lipases.

Key words: Brassica napus L., immuno-affinity, lipase, purification, triacylglycerol acyl hydrolas