Table 3. The activity and mass of LPL wild-type and mutants in transfected COS-1 cells.
| Plasmids (n=6) | Medium | Cell lysate | Specific activity | ||
|---|---|---|---|---|---|
| Activity(nmol/mL) | Mass(pg/mL) | Activity(nmol/mL) | Mass(pg/mL) | (nmol/pg) | |
| LPL-wt | 2.71±0.42 | 15.51±3.25 | 10.10±2.15 | 40.46±2.87 | 0.25±0.05 |
| LPL-310 | 2.00±0.31* | ND | 7.09±2.16* | 24.61±2.33*** | 0.28±0.11 |
| LPL-396 | 2.00±0.64* | ND | 12.25±1.71* | 50.76±4.29* | 0.25±0.04 |
| LPL-310396 | 1.29±0.16*** | ND | 15.17±1.53*** | 58.16±4.33*** | 0.25±0.02 |
| LV5 | 1.49±0.24*** | ND | 4.31±1.32*** | 17.19±3.35*** | 0.26±0.08 |
The plasmids of LPL wild-type, LPL-310, LPL-396, LPL-310396 and LV5 were transfected into COS-1 cells. Medium and cell lysates were collected after 20 units/mL heparin incubation. LPL activity and mass in the medium and cell lysates were quantified by enzyme-fluorescent method and ELISA, respectively. Detection limits of LPL activity and mass are 0.03 nmol/mL and 5 pg/mL, respectively. Each experiment was repeated by measuring six separate dishes. The activity and mass values are shown as mean±SD. ND, not detectable. *, P<0.05.***, P<0.01, significant differences from LPL wild-type. Specific activity is calculated by dividing LPL activity by LPL mass in the cell lysates.