Table 5.
Permeabilizing activity of WLIP and tolaasin I on vesicles of different lipid composition and a statistical analysis of their pore-formation mechanism.
| Lipid Compositiona (mol%)
|
WLIP
|
Tolaasin I
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| PC | SM | sterol | 1/C50b(μM−1) | K1c (M−1) | Md | K2e | 1/C50b (μM−1) | K1c (M−1) | Md | K2e |
| 100 | 0 | 0 | 0.59 ± 0.04 | 50 ± 20 | 8 ± 1 | 533 ± 451 | 2.8 ± 0.4 | 233 ± 52 | 6 ± 1 | 5.2 ± 2.6 |
| 50 | 50 | 0 | 1.41 ± 0.05 | 100 ± 30 | 6 ± 1 | 200 ± 340 | 4.9 ± 0.2 | 673 ± 179 | 6 ± 1 | 1.7 ± 1.1 |
| 50 | 33 | 16.5* | 0.70 ± 0.05 | 100 ± 30 | 12 ± 1 | 217 ± 247 | 2.8 ± 0.2 | 200 ± 50 | 6 ± 1 | 12 ± 12 |
| 50 | 16.5 | 33* | 0.59 ± 0.01 | 50 ± 20 | 8 ± 1 | 533 ± 451 | 1.2 ± 0.2 | 100 ± 30 | 7 ± 1 | 19.7 ± 17.4 |
| 50 | 0 | 50* | 0.45 ± 0.01 | 50 ± 20 | 11 ± 1 | 533 ± 451 | 0.4 ± 0.1 | 50 ± 20 | 7 ± 1 | 0.8 ± 0.3 |
| 50 | 33 | 16.5§ | 0.70 ± 0.03 | 100 ± 30 | 12 ± 1 | 413 ± 440 | 2.5 ± 0.2 | 250 ± 54 | 7 ± 1 | 2.8 ± 1.7 |
| 50 | 16.5 | 33§ | 0.59 ± 0.08 | 50 ± 20 | 8 ± 1 | 533 ± 451 | 1.3 ± 0.1 | 100 ± 30 | 7 ± 1 | 30 ± 20 |
| 50 | 0 | 50§ | 0.54 ± 0.01 | 50 ± 20 | 10 ± 1 | 533 ± 451 | 1.0 ± 0.2 | 50 ± 20 | 5 ± 1 | 30 ± 20 |
Lipid mixtures are reported on a molar base. PC: egg phosphatidylcholine; SM: sphyngomyelin; the sterol included in the vesicles was cholesterol* and ergosterol§.
The permeabilising activity is expressed as the reciprocal of the concentration of toxin causing 50% of calcein release (C50). Data are average ± S.D. of at least two different experiments.
The partition coefficient of toxin monomers into the liposome.
The number of monomers necessary for the formation of an active pore.
The aggregation process of membrane-inserted monomers.
Data are average ± S.D. of at least three different experiments.