Table 3. Enzyme activities in basolateral membrane (pellet B), microvilli and matrix vesicles extracted from Saos-2 cells.

Succinate dehydrogenase (marker of inner mitochondrial membrane), NADH oxidase (marker of both outer mitochondrial membrane and endoplasmic reticulum), acid phosphatase (marker of lysosomes), leucine aminopeptidase (marker of apical membranes) and alkaline phosphatase (marker of plasma membranes and MVs). Pellet A stands for cell debris, pellet B corresponds to basolateral membranes, supernatant C corresponds to microsomal and cytosolic fractions, pellet 2 corresponds to cell debris and supernatant 3 stands for extracellular matrix (see Fig. 4). ND: not detectable; E: enrichment. (Results are mean ± SD, n=3). Adapted from [32].

		Digest	Pellet A	Pellet B	Microvilli	Supernatant C	Pellet 2	MVs	Supernatant 3
Proteins	mg	30.4 ± 0.1	12.2. ± 0.8	2.4 ± 0.6	0.5 ± 0.1	5.8 ± 1.1	2.2 ± 0.2	0.7 ± 0.2	7.7 ± 1.7
	%	100	40	8	2	19	7	2	25
Succinate dehydrogenase	Umg−1	2.1 ± 0.1	4.3. ± 0.8	2.3 ± 0.4	ND	ND	2.1 ± 0.2	ND	ND
	%	100	80.7	8.7	ND	ND	7	ND	ND
	E	1	2	1.1	ND	ND	1	ND	ND
NADH oxidase	Umg−1	13.5 ± 1.2	24.4. ± 4.1	20.1 ± 5.8	5.6 ± 1.0	8.1 ± 2.2	7.2 ± 1.1	1.9 ± 0.6	ND
	%	100	72.6	11.8	0.6	11.5	3.8	0.3	ND
	E	1	1.8	1.5	0.4	0.6	0.5	0.1	ND
Acide phosphatase	Umg−1	2.3 ± 0.2	4.4. ± 0.3	2.6 ± 0.6	1.1 ± 0.2	ND	4.42 ± 0.8	0.7 ± 0.02	ND
	%	100	79	8.7	0.7	ND	12.7	0.7	ND
	E	1	2	1.2	0.5	ND	1.8	0.3	ND
Leucine aminopeptidase	Umg−1	1.0 ± 0.1	0.7. ± 0.1	1.2 ± 0.2	6.8 ± 0.8	0.8 ± 0.8	2.1 ± 0.3	5.3 ± 0.9	0.5 ± 0.1
	%	100	28.5	9.4	9.7	15	14.6	11.8	11.3
	E	1	0.7	1.2	6.6	0.8	2	5.1	0.5
Alkaline phosphatase	U Umg−1	8.4 ± 0.4	3.2 ± 0.2	7.1 ± 0.2	110 ± 6	2.1 ± 0.4	14.1 ± 2.4	121 ± 13	1.22 ± 1
	%	100	15	6.7	19.3	4.9	11.9	33.4	3.7
	E	1	0.4	0.9	13.1	0.3	1.7	14.4	0.1