Single-Molecule Detection of Insertion and Folding of OmpA in Droplet Interface Bilayers

Abstract

The Outer Membrane Proteins of E. coli are a family of membrane-spanning beta-barrels which enable vital communication with the surrounding environment. The folding and insertion of OmpA into the membrane is the archetype for beta-barrel protein folding. Here we monitor the folding dynamics of OmpA into Droplet Interface Bilayers using single-molecule FRET. Energy transfer reports on the folded state of individual molecules imaged using TIRF microscopy. We explore the kinetics of initial binding and subsequent insertion into the bilayer.