TABLE 1.

Triglyceride lipase and phospholipase activities of EL and EL-EL under conditions promoting different levels of cleavage

Wild-type EL and EL-EL were expressed in HEK293 cells under control conditions and under conditions promoting different levels of cleavage. HEK293 cells stably expressing profurin prevent EL cleavage, and HEK293 cells stably expressing PC5a promote the cleavage of EL. The triglyceride lipase activity (TG activity) and phospholipase activity (PL activity) of each conditioned medium were expressed in nanomoles of free fatty acid product (P) formed/h-ml of conditioned media as source of lipase. The activity values reported in this table are the mean values and the standard deviations (mean ± S.D., n = 3). The ratio of the triglyceride lipase to phospholipase activity (TG/PL ratio) represent the substrate specificity of the enzyme. The last column represents the mean values and the mean ± S.D. of the triglyceride/phospholipase ratios across independent experiments (n = 5 for HEK 293 cell media and n = 4 each for cell media from HEK293 cells expressing profurin or PC5a). Statistical analysis was run using an unpaired t test to determine whether the mean of the triglyceride/phospholipase ratios were significantly different (p < 0.05). The triglyceride/phospholipase ratios of EL-EL and wild-type EL were not statistically different experimentally whatever the cell types used for the transfection.

293 cells	Lipases	TG activity	PL activity	TG/PL ratio (mean ± S.D.)
		nmol P/h/ml	nmol P/h/ml
PC5a	EL	172.5 ± 8.4	92.7 ± 7.4	1.92 ± 0.12
	EL-EL	425.5 ± 8.6	173.1 ± 10.6	1.56 ± 0.62
	EL	265.9 ± 3.8	172.4 ± 1.1	1.56 ± 0.24
	EL-EL	484.9 ± 20.2	226.0 ± 11.3	1.46 ± 0.57
Profurin	EL	445.2 ± 10.5	306.5 ± 79.1	1.72 ± 0.24
	EL-EL	673.5 ± 22.1	313.1 ± 4.5	1.79 ± 0.58