TABLE 1.
Kinetic parameters for cholesterol efflux to ApoA-I from J774/BHK cells
| Apolipoprotein | FC efflux |
|||||
|---|---|---|---|---|---|---|
| J774 cells |
BHK cells |
|||||
| Relative Vmaxa | Km | Relative catalytic efficiencyb | Relative Vmaxc | Km | Relative catalytic efficiencyd | |
| μg Apo/ml | μg Apo/ml | |||||
| WT ApoA-I (H) | 1.0 | 5.7 ± 0.2 (n = 15) | 1.0 | 1.0 | 6.7 ± 0.4 (n = 12) | 1.0 |
| 1–189(H) | 1.8 ± 0.06 (n = 6) | 31.8 ± 1.7 (n = 6) | 0.3 | 1.8 ± 0.3 (n = 3) | 28.5 ± 6.1 (n = 3) | 0.4 |
| 190–243(H) | 0.8 ± 0.04 (n = 6) | 11 ± 1.2 (n = 6) | 0.4 | 1.4 ± 0.2 (n = 3) | 20.4 ± 4.0 (n = 3) | 0.45 |
| WT ApoA-I (M) | 2.5 ± 0.04 (n = 15) | 24 ± 0.6 (n = 15) | 0.6 | 1.5 ± 0.1 (n = 3) | 14.7 ± 2.0 (n = 3) | 0.7 |
| 1–186(M) | 1.8 ± 0.05 (n = 3) | 2.3 ± 0.2 (n = 3) | 4.4 | 1.4 ± 0.1 (n = 3) | 5.7 ± 1.0 (n = 3) | 1.6 |
| H1–189M187–240 | 1.6 ± 0.1 (n = 3) | 9.6 ± 1.3 (n = 3) | 0.9 | 1.3 ± 0.1 (n = 3) | 34.3 ± 2.3 (n = 3) | 0.25 |
| M1–186H190–243 | 1.3 ± 0.06 (n = 3) | 3.5 ± 0.5 (n = 3) | 2.1 | 1.5 ± 0.1 (n = 3) | 6.06 ± 1.0 (n = 3) | 1.7 |
a The cellular cholesterol released from J774 cells to 20 μg/ml of WT human apoA-I was 9 ± 3%/4 h (n = 21) (mean ± S.D.), and all Vmax values are normalized to this value.
b The catalytic efficiency (Vmax/Km) for WT human apoA-I-mediated efflux from J774 cells was 1.6 ± 0.5% FC efflux (4 h)−1 (μg apo/ml)−1 (mean ± S.D.), and all catalytic efficiencies are normalized to this value.
c The cellular cholesterol released from BHK cells to 20 μg/ml of WT human apoA-I was 28 ± 4%/4 h (n = 12), and all of Vmax values are normalized to this value.
d The catalytic efficiency (Vmax/Km) for WT human apoA-I-mediated efflux from BHK cells was 4.2 ± 0.6% FC efflux (4 h)−1 (μg apo/ml)−1, and all catalytic efficiencies are normalized to this value.