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bioRxiv · 10.1101/2023.06.01.543083

Characterisation of membrane protein interactions by peptidisc-mediated mass photometry

Young, J. W.·Pfitzner, E.·Kukura, P.·Robinson, C. V.
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Abstract

Membrane proteins perform a variety of critical functions in the cell, making many of them primary drug targets. At the same time, their preference for a lipid environment makes them challenging to study using established solution-based methods. Here, we show that peptidiscs, a recently developed membrane mimetic, provide an ideal platform to study membrane proteins and their interactions with mass photometry (MP) in detergent-free conditions. The mass resolution for membrane protein complexes is similar to that achievable with soluble proteins owing to the low carrier heterogeneity. Using two well-characterized bacterial membrane protein complexes - the ABC transporter BtuCD, and the Sec translocon - we show that MP can quantify interactions between peptidisc-reconstituted membrane protein receptors and their soluble protein binding partners. Using the BAM complex, we further show that MP reveals interactions between a membrane protein receptor and a bactericidal antibody. Our results highlight the utility of peptidiscs for membrane protein characterization in detergent-free solution and provide a rapid and powerful platform for quantifying membrane protein interactions.

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Young, J. W., Pfitzner, E., Kukura, P., Robinson, C. V.. 2023-06-02. Characterisation of membrane protein interactions by peptidisc-mediated mass photometry. https://doi.org/10.1101/2023.06.01.543083

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