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In-Situ Observation of Membrane Protein Folding during Cell-Free Expression.

ABSTRACT: Proper insertion, folding and assembly of functional proteins in biological membranes are key processes to warrant activity of a living cell. Here, we present a novel approach to trace folding and insertion of a nascent membrane protein leaving the ribosome and penetrating the bilayer. Surface Enhanced IR Absorption Spectroscopy selectively monitored insertion and folding of membrane proteins during cell-free expression in a label-free and non-invasive manner. Protein synthesis was performed in an optical cell containing a prism covered with a thin gold film with nanodiscs on top, providing an artificial lipid bilayer for folding. In a pilot experiment, the folding pathway of bacteriorhodopsin via various secondary and tertiary structures was visualized. Thus, a methodology is established with which the folding reaction of other more complex membrane proteins can be observed during protein biosynthesis (in situ and in operando) at molecular resolution.

SUBMITTER: Baumann A

PROVIDER: S-EPMC4792443 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

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In-Situ Observation of Membrane Protein Folding during Cell-Free Expression.

Baumann Axel A Kerruth Silke S Fitter Jörg J Büldt Georg G Heberle Joachim J Schlesinger Ramona R Ataka Kenichi K

PloS one 20160315 3

Proper insertion, folding and assembly of functional proteins in biological membranes are key processes to warrant activity of a living cell. Here, we present a novel approach to trace folding and insertion of a nascent membrane protein leaving the ribosome and penetrating the bilayer. Surface Enhanced IR Absorption Spectroscopy selectively monitored insertion and folding of membrane proteins during cell-free expression in a label-free and non-invasive manner. Protein synthesis was performed in ...[more]

PMID: 26978519

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