TABLE 2.
Interfacial kinetics of cPLA2α on vesicles
| Enzyme | Vesicle composition | appKCa | Percentage of maximal activity without calcium | Specific activity at saturating Ca2+ |
|---|---|---|---|---|
| μm | % | |||
| cPLA2α-PAP | [14C]PAPC | 0.7 ± 0.1 | 12 | 230 ± 8 |
| cPLA2α-505P | [14C]PAPC | 0.9 ± 0.1 | 8 | 380 ± 20 |
| cPLA2α-505P/727P | [14C]PAPC | 0.7 ± 0.2 | 8 | 405 ± 30 |
| cPLA2α-515P | [14C]PAPC | 0.5 ± 0.1 | 5 | 260 ± 8 |
| cPLA2α-PAP-K488N/K543N/K544N | [14C]PAPC | 0.7 ± 0.1 | 6 | 400 ± 8 |
| cPLA2α-PAP-K271N/K273N/R274N | [14C]PAPC | 0.3 ± 0.2 | 5 | 210 ± 12 |
| cPLA2α-PAP | 90% [14C]PAPC, 10% PIP2 | 0.66 ± 0.1 | 7 | 1030 ± 43 |
| cPLA2α-505P | 90% [14C]PAPC, 10% PIP2 | 0.55 ± 0.1 | 8 | 1450 ± 44 |
| cPLA2α-515P | 90% [14C]PAPC, 10% PIP2 | 0.3 ± 0.5 | 5 | 866 ± 38 |
| cPLA2α-PAP-K488N/K543N/K544N | 90% [14C]PAPC, 10% PIP2 | 1.0 ± 0.2 | 6 | 390 ± 10 |
| cPLA2α-PAP-K271N/K273N/R274N | 90% [14C]PAPC, 10% PIP2 | 1.5 ± 0.2 | 7 | 680 ± 10 |