Figure 4. Degradation of AMPs by cytoplasmic peptidase activity.

The parental NTHI strain was fractionated to obtain cytoplasm-enriched fractions. This fraction was combined with hBD-3 or LL37 in the presence or absence of a protease inhibitor cocktail (−/+ Inhibitor) and incubated for 0, 2, 5 or 13 hours. Samples were separated by SDS-PAGE on a 16.5% Tris-Tricine gel, and hBD3 or LL-37 was detected by immunoblot analysis. Samples were matched for viability and normalized for protein amount, as shown [C] for both hBD3 and LL-37.