Mammalian Membrane Receptors Expression as Inclusion Bodies in Escherichia coli
Integral membrane proteins, in particular receptors, regulate numerous physiological functions. The primary difficulty presented by their study in vitro is to obtain them in sufficient amounts in a functional state. Escherichia coli is a host of choice for producing recombinant proteins for structural studies. However, insertion of G-protein coupled receptors into its plasma membrane usually results in bacterial death. An alternative approach consists of targeting recombinant receptors to inclusion bodies, where they accumulate without affecting bacterial growth, and then fold them in vitro . We describe here a general approach that consists of accumulating the receptor in bacterial inclusion bodies, then purifying it under denaturing conditions. A simple assay is then described to screen for refolding conditions of the protein.
Key wordsEscherichia coli GPCR inclusion bodies membrane protein receptor refolding
- 3.Palczewski K, Kumasaka T, Hori T, Behnke CA, Motoshima H, Fox BA, Le Trong I, Teller DC, Okada T, Stenkamp RE, Yamamoto M, Miyano M (2000) Crystal structure of rhodopsin: a G protein-coupled receptor. Science 289:739–745Google Scholar
- 5.Rasmussen SG, Choi HJ, Rosenbaum DM, Kobilka TS, Thian FS, Edwards PC, Burghammer M, Ratnala VR, Sanishvili R, Fischetti RF, Schertler GF, Weis WI, Kobilka BK (2007) Crystal structure of the human beta2 adrenergic G-protein-coupled receptor. Nature 450:383–387Google Scholar
- 6.Warne T, Serrano-Vega MJ, Baker JG, Moukhametzianov R, Edwards PC, Henderson R, Leslie AG, Tate CG, Schertler GF (2008) Structure of a beta1-adrenergic G-protein-coupled receptor. Nature 454:486–491Google Scholar