Antibiotic translocation through porins studied in planar lipid bilayers using parallel platforms.
نویسندگان
چکیده
In general, the method of choice to characterize the conductance properties of channel-forming bacterial porins is electrophysiology. Here, the classical method is to reconstitute single porins into planar lipid bilayers to derive functional information from the observed channel conductance. In addition to an estimated pore size, ion selectivity or transport properties in general are of importance. For the latter, measuring the ion current fluctuation can provide some information about the mode of transport of charged molecules penetrating the proteins. For instance, increasing the external voltage modifies the residence time in the channel: charged molecules with the ability to permeate through channels will travel faster whereas non-permeating molecules get pushed to the constriction zone with enhanced residence time. Here, we are interested in the ability of antibiotics to permeate channels and compare different techniques to reveal fast events.
منابع مشابه
How β-Lactam Antibiotics Enter Bacteria: A Dialogue with the Porins
BACKGROUND Multi-drug resistant (MDR) infections have become a major concern in hospitals worldwide. This study investigates membrane translocation, which is the first step required for drug action on internal bacterial targets. beta-lactams, a major antibiotic class, use porins to pass through the outer membrane barrier of Gram-negative bacteria. Clinical reports have linked the MDR phenotype ...
متن کاملPermeation of antibiotics through Escherichia coli OmpF and OmpC porins: screening for influx on a single-molecule level.
A chip-based automated patch-clamp technique provides an attractive biophysical tool to quantify solute permeation through membrane channels. Proteo-giant unilamellar vesicles (proteo-GUVs) were used to form a stable lipid bilayer across a micrometer-sized hole. Because of the small size and hence low capacitance of the bilayer, single-channel recordings were achieved with very low background n...
متن کاملProtein translocation through anthrax toxin channels formed in planar lipid bilayers.
The 63-kDa fragment of the protective antigen (PA) component of anthrax toxin forms a heptameric channel, (PA63)7, in acidic endosomal membranes that leads to the translocation of edema factor (EF) and lethal factor (LF) to the cytosol. It also forms a channel in planar phospholipid bilayer membranes. What role does this channel play in the translocation of EF and LF? We report that after the 2...
متن کاملRefolded outer membrane protein A of Escherichia coli forms ion channels with two conductance states in planar lipid bilayers.
Outer membrane protein A (OmpA), a major structural protein of the outer membrane of Escherichia coli, consists of an N-terminal 8-stranded beta-barrel transmembrane domain and a C-terminal periplasmic domain. OmpA has served as an excellent model for studying the mechanism of insertion, folding, and assembly of constitutive integral membrane proteins in vivo and in vitro. The function of OmpA ...
متن کاملMicrofabricated teflon membranes for low-noise recordings of ion channels in planar lipid bilayers.
We present a straightforward, accessible method for the fabrication of micropores with diameters from 2 to 800 micro m in films of amorphous Teflon (Teflon AF). Pores with diameters </=40 micro m made it possible to record ion fluxes through ion channels in planar bilayers with excellent signal characteristics. These pores afforded: i), stable measurements at transmembrane voltages up to 460 mV...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Analyst
دوره 140 14 شماره
صفحات -
تاریخ انتشار 2015