Affinity Purification of Membrane β-Barrel Proteins via Biotin-Tagged Peptidiscs

β-barrel membrane proteins play a crucial role in bacterial pathogenesis and antibiotic resistance, making them a prime focus for the development of new antibiotics and therapeutics. However, their inherent hydrophobic nature and limited presence pose challenges for their high-throughput characterization using conventional methods. In this context, we present a simple but efficacious approach using peptidisc, a membrane mimetic, to overcome the low abundance and hydrophobicity of these proteins. Our methodology, illustrated here using Escherichia coli (E. coli) as a model organism, covers the entire process from outer membrane fraction preparation to data analysis. This detailed protocol outlines the purification of a diverse collection of β-barrel membrane proteins, rendering them water-soluble and readily amenable to mass spectrometry and downstream drug screening strategies.