The Lipid Cubic Phase as a Medium for the Growth of Membrane Protein Microcrystals

  • Zina Al-Sahouri
  • Ming-Yue Lee
  • Dianfan Li
  • Wei Liu
  • Martin Caffrey


The lipid-based bicontinuous cubic mesophase is a nanoporous membrane mimetic with applications in areas that include medicine, personal care products, foods, and the basic sciences. An application of particular note is as a medium in which to grow crystals of membrane proteins for structure determination by X-ray crystallography. At least two variations of the mesophase exist. One is the highly viscous cubic phase, known as the lipid cubic phase (LCP), which has well-developed long-range order. The other, the so-called sponge phase, is considerably more fluid and lacks long-range order. Both phase types have been shown to be amenable for growing microcrystals of membrane proteins and for use as a delivery medium to shuttle protein crystals to an X-ray free-electron laser beam for serial femtosecond crystallography. Here, we provide background on the physicochemical properties of these mesophases and how they function to grow microcrystals of membrane proteins. Protocols implemented for the generation and use of nanoliter volumes of mesophase of suitably high microcrystal density required for serial femtosecond crystallography are described. Prospects for future uses of lipid mesophases in the serial femtosecond crystallography arena are summarized.


Crystal structure Enzyme Membrane protein Mesophase Monoacylglycerol Serial femtosecond crystallography X-ray free-electron laser 



This review was supported in part by Science Foundation Ireland (12/IA/1255, 16/IA/4435; M.C.), the National Institutes of Health grants R21 DA042298 (W.L.), R01 GM124152 (W.L.), the National Science Foundation (STC award 1231306) (M.C., W.L.), and the Flinn Foundation Seed Grant (W.L.).


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Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Center for Applied Structural Discovery at the Biodesign Institute, School of Molecular SciencesArizona State UniversityTempeUSA
  2. 2.State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research CenterCAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of SciencesShanghaiChina
  3. 3.Membrane Structural and Functional Biology Group, School of Medicine and School of Biochemistry and ImmunologyTrinity College DublinDublinIreland

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