Fig. 6
From: A Protein Nanopore-Based Approach for Bacteria Sensing
Cartoon representation (not drawn to the scale) reflecting the putative role played by the CMA3 peptide adsorption to P.a., on the bacterial cell capture process. As compared to the control case (no peptide, a), the cationic CMA3 peptide (charge = + 8|e −| at pH = 7) adsorption to P.a. (b) determines a net decrease on the bacterial surface charge on the outer membrane (Q), at pH = 7. The charge reduction on bacterial surface leads to an augmented association rate of the P.a.-α-HL interactions, resulting from the reduced magnitude of electrostatic repulsive forces manifested between the negatively charged bacteria and the lumen entrance of the α-HL (Fp-b), which over-compensates for the reduced electrophoretic force (F elp) acting on the bacterium (see text). Around neutral pH, the net electric charge present at the entrance of α-HL’s lumen is ~ − 7|e −|