TABLE 1.
TB_KKG6K-induced leakage of microbial model membranesa
| Model | Lipid(s) and location | % Leakage |
|||
|---|---|---|---|---|---|
| TB_KKG6K |
PCγC-terminal (32 μM) | ||||
| 2 μM | 4 μM | 8 μM | |||
| Prokaryotic membrane | PG | 56.0 ± 4.0* (+40) | 57.7 ± 3.9* (+30) | 61.1 ± 4.1* (+20) | 1.9 ± 1 |
| PG-PE-CL | 5.3 ± 1.3 | 40.2 ± 0.9 | 61.5 ± 2.7 | −1.2 ± 1.6 | |
| Eukaryotic membrane | PC | 33.8 ± 3.0 | 40.6 ± 3.2 | 49.2 ± 4.5 | 1.4 ± 1.4 |
| Outer leaflet | |||||
| PC-sphingomyelin | 18.8 ± 3.1* (−44) | 26.5 ± 1.0* (−34) | 33.9 ± 2.0* (−31) | 0.6 ± 0.8 | |
| PC-ceramide | 17.9 ± 1.8* (−47) | 39.9 ± 2.4 | 44.8 ± 1.9 | 1.3 ± 0.2 | |
| Inner leaflet | |||||
| PC-PI | 37.7 ± 3.9 | 52.5 ± 2.4* (+29) | 56.5 ± 2.9* (+15) | 0.4 ± 0.5 | |
| PC-PE | 22.8 ± 1.3* (−32) | 31.5 ± 2.1* (−22) | 40.0 ± 3.1* (−19) | 1.4 ± 0.6 | |
| PC-PS | 22.6 ± 3.3* (−33) | 38.1 ± 10.5 | 47.4 ± 15.1 | 0.9 ± 2.7 | |
| PC-ergosterol | 9.8 ± 1.5* (−71) | 13.0 ± 0.6* (−68) | 16.9 ± 2.0* (−66) | 1.1 ± 0.9 | |
| PC-PE-ergosterol | 14.8 ± 0.8* (−56) | 17.1 ± 6.0* (−58) | 15.8 ± 1.3* (−68) | 1.7 ± 2.0 | |
| PC-PS-ergosterol | 21.8 ± 3.5* (−36) | 30.1 ± 4.6* (−26) | 46.3 ± 4.2 | 2.0 ± 1.4 | |
| Mitochondrial envelope | |||||
| PC-CL | 2.2 ± 0.8* (−93) | 9.9 ± 0.7* (−75) | 59.0 ± 5.8* (+20) | 0.7 ± 0.4 | |
Data represent leakage of 50 μM concentrations of model membranes composed of different lipids in response to exposure to 2 μM, 4 μM, or 8 μM TB_KKG6K, which corresponded to lipid:peptide molar ratios of 25:1, 12:1, and 6:1, respectively, determined after 30 min of incubation at 37°C. Data are relative mean ± SD leakage of two independent experiments performed in duplicates in the presence of the TB analog. The values were compared to those for the positive control (1% [wt/vol]) Triton-X), which represented 100% leakage. The relative change (as a percentage) in leakage of the different lipid combinations was compared to the values for PC-LUVs (in parentheses). PCγC-terminal (32 μM; lipid:peptide molar ratio of 1.5:1) served as a negative control. A two-way ANOVA, corrected for multiple comparisons by the Dunnett's test, was applied to calculate the significant differences between the mean leakage values of LUVs composed of distinct lipid formulations to those of the PC-LUVs. *, P ≤ 0.05.