SEC-SANS for structure determination for membrane proteins in polymer-stabilised nanodiscs

This proposal is a continuation from our upcoming experiment aimed at using Size-Exclusion Chromatography coupled with SANS (SEC-SANS) to ensure accurate measurement of membrane proteins supported in Poly(Styrene-Maleic Acid) (SMA) lipid-nanodiscs. These polymer-formed nanodiscs are an appealing choice compared to more traditional alternatives for protein extraction and structural studies, as preparations are stable, quick, low cost and can be produced in large quantities. In this proposal we propose to use again the membrane proteins gramicidin and REAMP within polymer-nanodiscs benchmarked in our upcoming experiment where polymer variant, concentration and deuteration conditions will be optimised. REAMP is a de novo membrane protein containing four alpha-helical transmembrane domains while gramicidin is readily available to facilitate initial scoping experiments using SEC-SANS.