Transmembrane protein rotaxanes reveal kinetic traps in the refolding of translocated substrates.

ABSTRACT: Understanding protein folding under conditions similar to those found in vivo remains challenging. Folding occurs mainly vectorially as a polypeptide emerges from the ribosome or from a membrane translocon. Protein folding during membrane translocation is particularly difficult to study. Here, we describe a single-molecule method to characterize the folded state of individual proteins after membrane translocation, by monitoring the ionic current passing through the pore. We tag both N and C termini of a model protein, thioredoxin, with biotinylated oligonucleotides. Under an electric potential, one of the oligonucleotides is pulled through a α-hemolysin nanopore driving the unfolding and translocation of the protein. We trap the protein in the nanopore as a rotaxane-like complex using stre

SUBMITTER: Feng J 

PROVIDER: S-EPMC7125113 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature