Electric translocation of ofluxacine through OmpF nanochannel

Nano-channel voltage sensitive forming protein (OmpF) is responsible for the selection and traffic of various molecules across the outer membrane of E.coli. Each monomer of the trimeric OmpF channel consists of 16 beta-strands forming a barrel-shaped nano-channel with exclusion limit of about 600Da. The channel controls the influx of Ofluxacine administered to tackle with the urinary infection caused by E.coli. The size and charge of antibiotic play important roles and finding the means to ease the translocation and lowering the administration dosage will serve patients with infection in particular those affected by MDR bacteria. In this work, electric field was applied to ease and study the translocation of Ofloxacin through single nanopore at certain physico-chemical condition by means of voltage clamp technique in real time. Our results revealed changes in the voltage dependent gating and ion current deviation during translocation of Ofloxacin through the channel that opposed the electric field when it reached the constriction zone of the channel, closing it at ±35 mV. There is a special arrangement of amino acids side chains at the constriction zone forming a powerful perpendicular plain of electric field which define the gating property, selects certain ions and obstructs antibiotic translocation by means of electrostatic interactions. Here, we present the results of changes in the physico-chemical condition of the medium, including pH and ionic strength at different membrane potential. These factors serve as basic means for tailoring appropriate cocktail and configuration of the administered drug to achieve the most efficiency against the bacteria.