Membrane protein solubilization and structure determination using de novo–designed proteins
- Ljubica Mihaljevic
- David E. Kim
- Pooja D. Bandawane
- Helen E. Eisenach
- Andrew J. Borst
- Alexis Courbet
- Connor Weidle
- Kenneth D. Carr
- Everton Bettin
- Qiushi Liu
- Aldo T. Trejos
- Sagardip Majumder
- Surabhi Kokane
- Alexander Stevens
- Edin Muratspahić
- Thomas Schlichthaerle
- Marc Expòsit
- Xinting Li
- Mila Lamb
- Analisa Nicole Azcárraga Murray
- Rashmi Ravichandran
- Elizabeth C. Williams
- Shuyuan Hu
- Lynda Stuart
- Linda Grillová
- Nicholas R. Thomson
- Michael Landreh
- Pengxiang Chang
- Lorenzo Giacani
- Melissa J. Caimano
- Kelly L. Hawley
- Neil P. King
- David Baker
2026-07-02
Developing therapies and vaccines against integral membrane proteins is hindered by their extensive hydrophobic surfaces, which complicate production and structural analysis. Here, we describe a general deep learning–based design approach for solubilizing native membrane proteins while preserving their sequence, fold, active-site, and ligand-binding properties. Genetically encoded de novo protein WRAPs [water-soluble RFdiffused amphipathic proteins] surround the lipid-interacting hydrophobic surfaces, rendering them thermostable and water-soluble without the need for detergents. We design WRAPs for both monomeric and oligomeric beta-barrel outer membrane proteins and helical multipass transmembrane proteins. A 2.95-angstrom-resolution cryo–electron microscopy structure of WRAPed mycobacterial porin demonstrates that WRAPs can be used for the structural determination of membrane proteins in solution. As a step toward syphilis vaccine development, we generated soluble versions of Treponema pallidum antigens.