Furosemide blocks the anion channel caused by Staphylococcus aureus α-hemolysin

To investigate the effect of furosemide on Staphylococcus aureus α-hemolysin (α-HL) channel in planar lipid bilayers by electrophysiological characterization and molecular docking studies. Planar lipid bilayer membranes were prepared and α-HL (0.07 mg/mL) was added to the standard solution in cis compartment of the experimental chamber. All experiments were performed at room temperature using an Axopatch 200A amplifier in the voltage clamp mode. At pH 7.5, α-HL channels were usually in a high conductance ~4 nS and rarely switch to low conductance states. After the ion channel was incorporated in bilayer membrane, the furosemide was also added to the standard solution to the cis compartment. To docking studies, atomics coordinates for the α-HL heptameric channel was retrieved from PDB ID (7AHL) and the structure of furosemide was removed from the PubChem, their coordinates were built and minimized with Avogadro software. The molecular docking experiments were performed using the Dockthor online. The furosemide inhibited (P<0.05) conductance α-HL channel and it was a voltage-dependent manner. The two best docking solutions and the α-HL channel were evaluated, it was observed the connection mode with the highest affinity of interaction has a greater number of hydrogen bonding. The residues were 113 and 147 that form the remainders of the constriction α-HL channel. In conclusion, furosemide blocks ion currents in the constriction of channel caused by Staphylococcus aureus α-hemolysin.