Electrostatics Drive Oligomerization and Aggregation of Human Interferon Alpha-2a

Area of Science:

• Biophysics
• Protein Science
• Drug Development

Background:

• Protein aggregation is a significant challenge in therapeutic development, potentially causing loss of function and immunogenicity.
• Current strategies to mitigate aggregation include formulation optimization and protein engineering, both with limitations.

Purpose of the Study:

• To biophysically characterize the oligomerization and aggregation of Interferon alpha-2a (IFNα-2a).
• To elucidate the molecular mechanisms driving IFNα-2a self-assembly.
• To identify strategies for preventing detrimental protein aggregation.

Main Methods:

• High-throughput screening
• Small-angle X-ray scattering (SAXS)
• Analytical ultracentrifugation (AUC)
• Metropolis Monte Carlo simulations

Main Results:

• IFNα-2a forms soluble oligomers via a pH and concentration-dependent equilibrium.
• Insoluble aggregates form near the isoelectric point (pI ≈ 6) and can be prevented by salt addition.
• Monomer attraction is driven by dipole-dipole interactions, while repulsion is governed by monopole-monopole interactions based on protein charge.

Conclusions:

• Combining experimental and computational methods provides a systematic approach to understanding protein aggregation.
• The findings offer insights into controlling IFNα-2a aggregation for improved therapeutic applications.
• This study lays the groundwork for designing effective strategies to prevent protein aggregation in therapeutics.