Expression of human peripheral cannabinoid receptor for structural studies

Authors

  • Alexei A. Yeliseev,

    Corresponding author
    1. Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892, USA
    • Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA; fax: (301) 594-0035.
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  • Karen K. Wong,

    1. Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892, USA
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  • Olivier Soubias,

    1. Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892, USA
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  • Klaus Gawrisch

    Corresponding author
    1. Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892, USA
    • Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA; fax: (301) 594-0035.
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Abstract

Human peripheral-type cannabinoid receptor (CB2) was expressed in Escherichia coli as a fusion with the maltose-binding protein, thioredoxin, and a deca-histidine tag. Functional activity and structural integrity of the receptor in bacterial protoplast membranes was confirmed by extensive binding studies with a variety of natural and synthetic cannabinoid ligands. E. coli membranes expressing CB2 also activated cognate G-proteins in an in vitro coupled assay. Detergent-solubilized receptor was purified to 80%–90% homogeneity by affinity chromatography followed by ion-exchange chromatography. By high-resolution NMR on the receptor in DPC micelles, it was determined that purified CB2 forms 1:1 complexes with the ligands CP-55,940 and anandamide. The receptor was successfully reconstituted into phosphatidylcholine bilayers and the membranes were deposited into a porous substrate as tubular lipid bilayers for structural studies by NMR and scattering techniques.

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