8.D.5.  The Bicelle (Bicelle) Family 

Bicelles are detergent-stabilized phospholipid bilayer discs into which membrane proteins (MPs) can be reconstituted for biophysical studies. Poulos et al. 2015 reviewed advances and emerging concepts in employing bicelles for the crystallization and structure determination of MPs. They discuss variations of established procedures as well as alternative approaches, and they present a summary and analysis of the conditions used for bicelle-mediated MP crystallization.

Bicelles (Dürr et al. 2012) are obtained by thorough water mixing of long chain and short chain lipids that may take the form of membranous discs of 10-50 nm. Temperature-composition-hydration diagrams have been established for phosphatidylcholines, and they show limited domains of existence (Dufourc 2021). Bicelles can be doped with charged lipids, surfactants or with cholesterol and offer a wide variety of membranous platforms for structural biology. Internal dynamics as measured by solid-state NMR is similar to that of liposomes in their fluid phase. Parmar et al. 2016 have reviewed the use and applicability of bicelles and other artificial lipid matrices for the study of integral membrane proteiins. Small isotropic bicelles are versatile membrane mimetics, which, in contrast to micelles, provide a lipid bilayer and are at the same time suitable for solution-state NMR studies (Liebau et al. 2017).



Dufourc, E.J. (2021). Bicelles and nanodiscs for biophysical chemistry. Biochim. Biophys. Acta. Biomembr 1863: 183478.

Dürr, U.H., M. Gildenberg, and A. Ramamoorthy. (2012). The magic of bicelles lights up membrane protein structure. Chem Rev 112: 6054-6074.

Liebau, J., W. Ye, and L. Mäler. (2017). Characterization of fast-tumbling isotropic bicelles by PFG diffusion NMR. Magn Reson Chem 55: 395-404.

Parmar, M.J., C.d.e.M. Lousa, S.P. Muench, A. Goldman, and V.L. Postis. (2016). Artificial membranes for membrane protein purification, functionality and structure studies. Biochem Soc Trans 44: 877-882.

Poulos, S., J.L. Morgan, J. Zimmer, and S. Faham. (2015). Bicelles coming of age: an empirical approach to bicelle crystallization. Methods Enzymol 557: 393-416.