Table 1.
Activities of marker enzymes in the luminal membrane vesicles isolated from pig and human colon
| Tissue source | Enzyme | Specific activity (nmol min−1 (mg protein)−1) | Enrichment1 | Recovery2 (%) |
|---|---|---|---|---|
| Pig | Cysteine-sensitive alkaline phosphatase | 11.0 ± 2 | 10.0 ± 3.0 | 22.0 |
| α-Mannosidase | 2.6 ± 0.6 | 1.5 ± 0.5 | 2.2 | |
| Tris-resistant α-glucosidase | 1.8 ± 0.3 | 2.2 ± 0.9 | 1.5 | |
| Succinate dehydrogenase | 4.7 ± 1 | 1.4 ± 2.1 | 4.2 | |
| Pig/human | Na+-K+-ATPase | 11.0 ± 2.5 | 0.5 ± 1.0 | 0.5 |
| Human | Cysteine-sensitive alkaline phosphatase | 6.7 ± 3.0 | 16.8 ± 3.0 | 24.5 |
| Succinate dehydrogenase | 1.1 ± 1 | 1.5 ± 0.1 | 2.7 |
LMV were isolated as described in Methods. All enzyme assays were carried out in triplicate and the activities are expressed as means ± s.e.m. for 3 experiments.
1
Enrichment is the ratio of the specific activity of the enzyme in the vesicle fraction over the specific activity present in the homogenate.
2
Recovery is the total activity of the enzyme in the vesicle fraction as a percentage of the total activity present in the homogenate.