Lipase activity in germinating sunflower seedlings

Studying lipase in germinating sunflower seedlings, we looked for an activator of the lipolytic activity. In the presence of 1.25 mM ATP, the enzyme activity increased 2-fold. Lipid-body lipase solubilization was realized using two detergents: Tween 80 and CHAPS. Lipolytic activity was increased 10-fold in the presence of 2 % (w/v) CHAPS, showing the probable 'complexity' of the enzyme. Looking for the possible lipolytic activity of the 10 000 g pellet we detected the presence of the enzyme. The pellet extract was mixed, in a range of concentrations, with the oil-body fraction. The resulting lipolytic activity was 4-fold higher. These results give clues as to the subcellular distribution of lipase and its intracellular transport.