Volume 95 Issue 15 | p. 11 | Concentrates
Issue Date: April 10, 2017

Getting GPCRs into liposomes

Technique extracts the receptors from cells and puts them in proteoliposomes while maintaining their function
Department: Science & Technology
News Channels: JACS In C&EN
Keywords: biochemistry, acs meeting news, liposomes, G protein-coupled receptors, GPCRs
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In INSYRT, GPCR-containing cells are treated with an acyl maltose thioester (step not shown), forming micelles. Native chemical ligation combines the micelles with lysolipids, forming phospholipids that assemble into GPCR-containing proteoliposomes.
Credit: Adapted from JACS
INSYRT schematic shows that GPCR-containing cells are treated with an acyl maltose thioester, forming micelles. Native chemical ligation then combines the micelles with lysolipids, forming phospholipids that assemble into GPCR-containing proteoliposomes.
 
In INSYRT, GPCR-containing cells are treated with an acyl maltose thioester (step not shown), forming micelles. Native chemical ligation combines the micelles with lysolipids, forming phospholipids that assemble into GPCR-containing proteoliposomes.
Credit: Adapted from JACS

G protein-coupled receptors (GPCRs) are key drug targets and important signaling proteins embedded in cell membranes. To study the proteins’ specific signaling interactions more easily by eliminating the complexities of the cellular environment, researchers often use detergents to extract them from cell membranes and then reconstitute the receptors in synthetic membranes. The detergents can modify ligand binding interactions and other native properties of GPCRs, so researchers must use dialysis or adsorbents to remove detergents before studying the reconstituted proteins. A team led by Neal Devaraj and Roger Sunahara of the University of California, San Diego, developed a GPCR reconstitution technique that doesn’t require detergent cleanup (J. Am. Chem. Soc. 2017, DOI: 10.1021/jacs.6b12830). In the technique, called in situ lipid synthesis for protein reconstitution technology (INSYRT), the scientists use acyl maltose thioesters to extract GPCRs from cells, forming micelles containing the proteins. They then use native chemical ligation to combine acyl groups in the micelles with lysolipids, forming phospholipids that assemble spontaneously into spherical GPCR-containing proteoliposomes. The thioesters don’t survive the reaction and therefore don’t have to be removed. In a presentation at the ACS meeting, Devaraj showed that INSYRT could reconstitute the adenosine A2A receptor in proteoliposomes, where the receptor maintained its natural function.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society

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