Engineering a Coiled-Coil Protein for DARPin Presentation as a Potent SARS-CoV-2 Therapeutic

Area of Science:

• Biotechnology
• Protein Engineering
• Virology

Background:

• The COVID-19 pandemic highlighted the need for adaptable therapeutic strategies against rapidly mutating viruses like SARS-CoV-2.
• Traditional monoclonal antibodies face challenges in speed, cost, and complexity for emerging viral threats.
• Viral evolution necessitates novel platforms for rapid development of effective treatments.

Purpose of the Study:

• To develop a modular protein-based therapeutic platform for rapid adaptation against viral variants.
• To engineer fusion proteins combining Designed Ankyrin Repeat Proteins (DARPins) with a hexameric coiled coil (CC-HEX) for enhanced neutralization and pharmacokinetics.
• To evaluate the efficacy of these HEX-DARPin fusion proteins against SARS-CoV-2 variants and assess their therapeutic potential.

Main Methods:

• Rational protein design was employed to create modular fusion proteins (HEX-DARPins).
• DARPins, small antibody mimetics, were fused with a self-assembling hexameric coiled coil (CC-HEX).
• Neutralization assays using SARS-CoV-2 pseudoviruses and in vivo pharmacokinetic studies in mice were conducted.

Main Results:

• HEX-DARPins demonstrated potent neutralization against multiple SARS-CoV-2 pseudovirus variants.
• Fusion proteins incorporated both viral neutralization and serum albumin-binding functions.
• Albumin binding led to prolonged serum concentration and enhanced lung delivery in a murine model.

Conclusions:

• HEX-DARPin fusion proteins represent a promising therapeutic strategy for COVID-19 treatment.
• This platform offers modularity and adaptability for developing drugs against future viral pathogens.
• The study establishes a novel approach for pandemic preparedness through advanced protein engineering.