title: Biophysical characterization of in- and efflux in Gram-negative bacteria.
abstract: Gram-negative bacteria developed a number of tools to avoid accumulation of cell-toxic compounds. The outer membrane as a first defense system is tightly packed reducing permeation through the lipid membrane. Water-soluble compounds may penetrate through membrane channels called porins. Once inside the periplasmic space special enzymes may welcome the foreign molecule for inactivation. The molecules entering the inner membrane will be harvested by efflux pumps and ejected back to the extra-cellular space. Bacteria modulate all these barriers through the level of protein expression or mutations. In order to understand the function of the involved proteins a quantification of the individual transport elements is necessary. Here we describe recent biophysical methods to characterize molecular transport across membranes.
authors.affiliation: Jacobs University Bremen, School of Engineering and Science, 28759 Bremen, Germany.
authors.forename: Helge
authors.initials: H
authors.lastname: Weingart
authors.forename: Mircea
authors.initials: M
authors.lastname: Petrescu
authors.forename: Mathias
authors.initials: M
authors.lastname: Winterhalter
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D001692:Biological Transport; D002463:Cell Membrane Permeability / Q000502:physiology; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial; D006090:Gram-Negative Bacteria / Q000378:metabolism* / Q000502:physiology; D026901:Membrane Transport Proteins / Q000378:metabolism; D018272:Porins / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D018272:Porins