Fig. 3: Impact of lamellin-3K on cell wall integrity and viability.

a NS-TEM images of E. coli treated with 5 μM 3K in water, highlighting the supramolecular structures forming in situ. The leakage of cell content can also be clearly observed along with the diffused cell wall. Scale bar: 100 nm (inset shows the bacterial surroundings and displays the size distribution of lamellae width. Scale bar: 2 μm). For more details, see Supplementary Fig. 26 and Supplementary Table 6. Measurements were repeated three times and similar results were obtained. b Cytotoxicity activity of 3K against E. coli in water and PBS media represented by red and black lines (sigmoid fits), respectively. Note the higher antibacterial activity in water vs. PBS. The IC₅₀ values were calculated to be 1.24 ± 5.0x10⁻⁴ μM for 3K in water and 11.6 ± 1.48 μM for 3K in PBS (mean ± SEM, n = 3 biological replicates). c Cytotoxic activity of 3K on human model cells (MonoMac 6) in Tris-HCl and RPMI media displayed as red and black lines respectively. No significant toxicity was detected up to 80 μM in phosphate-free and phosphate-containing media. The given values represent the calculated IC₅₀ values obtained from the dose-response curves, after fitting with non-linear regression using the GraphPad Prism program. The IC₅₀ values are represented as mean ± SEM which are 112.2 ± 8.4 μM for 3K in Tris-HCl and 126 ± 7.1 μM for 3K in RPMI media (n = 4, biological replicates). For more details, see Supplementary Fig. 30 and Supplementary Table 7.