Journal
JOURNAL OF MOLECULAR BIOLOGY
Volume 408, Issue 4, Pages 599-615Publisher
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jmb.2011.02.051
Keywords
GPCR; directed evolution; stability; protein engineering; expression in E. coli
Categories
Funding
- Forschungskredit of the University of Zurich
- Swiss National Science Foundation (National Center of Competence in Research in Structural Biology)
Ask authors/readers for more resources
We recently developed a display method for the directed evolution of integral membrane proteins in the inner membrane of Escherichia coli for higher expression and stability. For the neurotensin receptor 1, a G-protein-coupled receptor (GPCR), we had evolved a mutant with a 10-fold increase in functional expression that largely retains wild-type binding and signaling properties and shows higher stability in detergent-solubilized form. We have now evolved three additional human GPCRs. Unmodified wild-type receptor cDNA was subjected to successive cycles of mutagenesis and fluorescence-activated cell sorting, and functional expression could be increased for all three GPCR targets. We also present a new stability screening method in a 96-well assay format to quickly identify evolved receptors showing increased thermal stability in detergent-solubilized form and rapidly evaluate them quantitatively. Combining the two methods turned out to be very powerful; even for the most challenging GPCR target the tachykinin receptor NK(1), which is hardly expressed in E. coli and cannot be functionally solubilized receptor mutants that are functionally expressed at 1 mg/llevels in E. coli and are stable in detergent solution could be quickly evolved. The improvements result from cumulative small changes in the receptor sequence. This combinatorial approach does not require preconceived notions for designing mutations. Our results suggest that this method is generally applicable to GPCRs. Existing roadblocks in structural and biophysical studies can now be removed by providing sufficient quantities of correctly folded and stable receptor protein. (C) 2011 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available