Optimized in vitro and in vivo expression of proteorhodopsin: A seven-transmembrane proton pump
Journal article, 2008

Proteorhodopsin is an integral membrane light-harvesting proton pump that is found in bacteria distributed throughout global surface waters. Here, we present a protocol for functional in vitro production of pR using a commercial cell-free synthesis system yielding 1.0 mg purified protein per milliliter of cell lysate. We also present an optimized protocol for in vivo over-expression of pR in Escherichia coli, and a two-step purification yielding 5 mg of essentially pure functional protein per liter of culture. Both approaches are straightforward, rapid, and easily scalable. Thus either may facilitate the exploitation of pR for commercial biotechnological applications. Finally, the implications of some observations of the in vitro synthesis behavior, as well as preliminary results towards a structural determination of pR are discussed.

Membrane protein

Functional expression




Pontus Emanuel Gourdon

Chalmers, Chemical and Biological Engineering, Molecular Imaging

Anna Alfredsson

University of Gothenburg

Anders Pedersen

University of Gothenburg

Erik Malmerberg

University of Gothenburg

Anna Maria Nyblom

Chalmers, Chemical and Biological Engineering, Molecular Imaging

Mikael Widell


Ronnie Berntsson


University of Groningen

Jarone Pinhassi

Linnaeus University

Marc Braiman

Syracuse University

Örjan Hansson

University of Gothenburg

Nicklas Bonander

University of Gothenburg

B Göran Karlsson

University of Gothenburg

Richard Neutze

University of Gothenburg

Protein Expression and Purification

1046-5928 (ISSN) 1096-0279 (eISSN)

Vol. 58 1 103-113

Subject Categories

Chemical Sciences



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4/5/2019 1