Table 3.
Acyl transfer on peptide HDL substrates
MBD indicates membrane-binding domain; apoA-I? indicates disease-related surface-exposed residues that could potentially bind apoA-I.
| Variant | Location | Vmax | Km | Vmax/Kd | Sig.a | n |
|---|---|---|---|---|---|---|
| μm/h | μm | |||||
| WT | 20 ± 0.3b | 6.2 ± 0.3 | 3.2 | 21 | ||
| ΔNΔC | NDc | ND | ** | 3 | ||
| S181A | Active site | ND | ND | ** | 3 | |
| W48A | MBD | 55 ± 17 | 173 ± 67 | 0.32 | * | 3 |
| L70S | MBD | 21 ± 6 | 68 ± 30 | 0.31 | * | 3 |
| T123A | ApoA-I? | 4.1 ± 1 | 18 ± 10 | 0.23 | ** | 3 |
| T123Id | ApoA-I? | 2.3 ± 2 | 26 ± 60 | 0.088 | * | 3 |
| F382A | ApoA-I? | 0.72 ± 0.2 | 0.14 ± 1 | 5.1 | ** | 6 |
| F382Vd | ApoA-I? | ND | ND | ** | 3 | |
| F382E | ApoA-I? | 0.95 ± 0.2 | ND | ** | 3 | |
| N131A | ApoA-I? | 36 ± 1 | 10 ± 0.9 | 3.6 | NS | 3 |
| N131Dd | ApoA-I? | 2.6 ± 0.9 | 9.2 ± 9 | 0.28 | ** | 3 |
| N391A | ApoA-I? | 3.4 ± 0.4 | 4.0 ± 2 | 0.85 | ** | 3 |
| N391Sd | ApoA-I? | 6.2 ± 0.5 | 3.6 ± 1 | 1.7 | * | 3 |
| G230Rd | Lid | 1.8 ± 0.3 | 2.3 ± 2 | 0.78 | ** | 3 |
| P232A | Lid | 7.6 ± 0.7 | 6.2 ± 2 | 1.2 | * | 3 |
| I233A | Lid | 12 ± 1 | 29 ± 5 | 0.41 | * | 3 |
| I233E | Lid | 1.1 ± 0.2 | ND | ** | 3 | |
| M234A | Lid | 23 ± 0.9 | 9.4 ± 1 | 2.4 | NS | 3 |
| S235A | Lid | 7.80 ± 0.5 | 9.3 ± 2 | 0.84 | * | 3 |
| S236A | Lid | 23 ± 0.9 | 11 ± 1 | 2.1 | NS | 3 |
| Δlid | Lid | 0.78 ± 0.4 | 10 ± 20 | 0.078 | ** | 9 |
| Δlid/F382A | Lid/ApoA-I? | 0.28 ± 0.2 | ND | ** | 3 | |
| LPLA2lid | Lid | 0.48 ± 0.2 | ND | ** | 3 | |
| LPLA2αA | αA–αA′ loop | 0.57 ± 0.1 | ND | ** | 3 |
a Sig. represents significance compared with WT using a two-tailed t-test. NS indicates not significant. *, 0.01 < p < 0.05; **, 0.001 < p < 0.01.
b Error represents standard deviation.
c ND = not determined; signal was too low for an accurate fit.
d Entry indicates disease-related mutants.