Figure 3 : Permeabilization properties of the LLO Y406A mutant.

From: Engineering a pH responsive pore forming protein

Figure 3

(a) Hemolysis maximal rate (OD min−1) at different protein concentrations of LLO (solid circles) compared to Y406A (solid squares). PFO (open circles) and a corresponding PFO Y381A mutant (open squares) are shown for comparison. Experiments were performed at pH 7.4 and room temperature. (b) Concentration of LLO or Y406A needed to achieve half of the maximal hemolysis rate at different pH values. n.a., not active. Symbols as in 3a. (c) Calcein release from LUVs induced by the LLO (left) and Y406A mutant (right). The concentration of proteins was 188 nM. (d) Fold change of hemolytic activity of LLO (red) and LLO mutants at position 406 tested at pH 7.4 and 5.7. Higher value represents a more pH-dependent hemolytic behavior. PFO (white) and PFO Y381A mutant (black) are shown for comparison. (e) Fold change of hemolytic activity of LLO (red) and a set of LLO mutants. Mutants have 1 to 4 point mutations that are coded with an indication of the mutated residue (Y406A, D208E, E247M, D320K).