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Publication Abstract from PubMed

In meso crystallization of membrane proteins relies on the use of lipids capable of forming a lipidic cubic phase (LCP). However, almost all previous crystallization trials have used monoacylglycerols, with 1-(cis-9-octadecanoyl)-rac-glycerol (MO) being the most widely used lipid. We now report that EROCOC17+4 mixed with 10% (w/w) cholesterol (Fig. 1) serves as a new matrix for crystallization and a crystal delivery medium in the serial femtosecond crystallography of Adenosine A2A receptor (A2AR). The structures of EROCOC17+4-matrix grown A2AR crystals were determined at 2.0 A resolution by serial synchrotron rotation crystallography at a cryogenic temperature, and at 1.8 A by LCP-serial femtosecond crystallography, using an X-ray free-electron laser at 4 and 20 degrees C sample temperatures, and are comparable to the structure of the MO-matrix grown A2AR crystal (PDB ID: 4EIY). Moreover, X-ray scattering measurements indicated that the EROCOC17+4/water system did not form the crystalline LC phase at least down to - 20 degrees C, in marked contrast to the equilibrium MO/water system, which transforms into the crystalline LC phase below about 17 degrees C. As the LC phase formation within the LCP-matrix causes difficulties in protein crystallography experiments in meso, this feature of EROCOC17+4 will expand the utility of the in meso method.

Isoprenoid-chained lipid EROCOC17+4: a new matrix for membrane protein crystallization and a crystal delivery medium in serial femtosecond crystallography.,Ihara K, Hato M, Nakane T, Yamashita K, Kimura-Someya T, Hosaka T, Ishizuka-Katsura Y, Tanaka R, Tanaka T, Sugahara M, Hirata K, Yamamoto M, Nureki O, Tono K, Nango E, Iwata S, Shirouzu M Sci Rep. 2020 Nov 9;10(1):19305. doi: 10.1038/s41598-020-76277-x. PMID:33168855^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.