ISIS Neutron and Muon Source Data Journal

Conformational study of membrane proteins in magnetically aligned positive bicelles

Abstract: Membrane protein structure is difficult to study and studies rely on membrane mimetics to retain protein fold. Bicelles are one such mimetic, in which lipid disks supporting folded membrane proteins are solubilised by detergent. Scattering techniques offer insights into protein conformation with SANS uniquely permitting studies of membrane proteins in contrast-matched lipid. We have developed sample environment at ZOOM for magnetic alignment of bicelles, which permits axial alignment of bicelles and embedded proteins with discotic axes perpendicular to the aligning magnetic field. This leads to cylindrical orientational distribution of the observed proteins, which leads to complications in conformational analysis. In this study, we propose a mimetic system, which leads to coaxial alignment of bicelle disks and embedded membrane proteins with the aligning field that removes orientational dispersion and leads to unique dimensional presentation in X and Y observations. This offers a direct measure of axial and mean lateral dimensions of membrane proteins. We achieve this alignment by switching the sign of bicellar diamagnetic susceptibility anisotropy to positive, which aligns orientational torque with the positive torque from protein helices. We propose to use SANS at ZOOM to characterise scattering dimensions from deuterated membrane helical bundles embedded in protonated bicelles aligned in positive sense by lanthanide paramagnetic centres associated with bicellar lipid.

Principal Investigator: Professor Boyan Bonev
Local Contact: Dr James Doutch
Experimenter: Dr Alice Atkins
Experimenter: Dr WEN JUNG LU

DOI: 10.5286/ISIS.E.RB2610001

ISIS Experiment Number: RB2610001

Publisher: STFC ISIS Neutron and Muon Source

Data format: RAW/Nexus
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Data Citation

The recommended format for citing this dataset in a research publication is as:
[author], [date], [title], [publisher], [doi]

For Example:
Professor Boyan Bonev et al; (2026): Conformational study of membrane proteins in magnetically aligned positive bicelles, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB2610001

Data is released under the CC-BY-4.0 license.