Designed Transmembrane Proteins Inhibit the Erythropoietin Receptor in a Custom Binding Topology

Area of Science:

• Membrane protein biophysics
• Computational protein design
• Molecular pharmacology

Background:

• Transmembrane (TM) domains are crucial for protein function and are challenging therapeutic targets.
• Existing designed TM domain-targeting agents mimic natural interactions.
• Targeting membrane proteins in custom topologies remains an unmet challenge.

Approach:

• Utilized computational design to create de novo TM proteins.
• Engineered TM proteins to target the erythropoietin receptor (EpoR) TM domain.
• Designed a custom binding topology to compete with EpoR homodimerization.

Key Points:

• Designed TM proteins successfully complex with EpoR in mammalian cells.
• Inhibition of erythropoietin-induced cell proliferation was observed.
• In vitro studies confirmed competitive disruption of EpoR homodimerization.
• Structural characterization validated the designed antiparallel TM helix complex at 1:1 stoichiometry.

Conclusions:

• Demonstrated the feasibility of designing de novo TM proteins targeting specific membrane protein TM domains.
• Established a new paradigm for targeting membrane proteins in custom topologies.
• Opened avenues for developing novel therapeutics against membrane protein targets.