Nanodiscs formation process studied by contrast variation-SANS

Membrane proteins are essential for cellular communication and are frequently key targets for pharmaceutical intervention. However, their structural and dynamical characterization remains limited due to challenges associated with protein production and in situ analysis. Recent advances in cryo-electron microscopy have improved access to high-resolution membrane protein structures, yet the complex interplay between membrane proteins and lipids in their native environment remains insufficiently understood. Nanodiscs provide a highly effective platform for studying membrane proteins in a physiologically relevant environment and, with the recent development of "stealth nanodiscs," have become particularly promising for structural investigations using SANS. Here, by combining nanodiscs with contrast variation, we present a case study that characterizes the formation and structure of a protein-scaffold nanodisc through the joint analysis of small-angle neutron and X-ray scattering (SANS and SAXS). By enabling in situ investigations of protein-lipid interactions, these nanodiscs constitute a powerful tool for advancing our understanding of membrane protein structure and dynamics.