Journal article
Electrostatics Drive Oligomerization and Aggregation of Human Interferon Alpha-2a
Aggregation is a common phenomenon in the field of protein therapeutics and can lead to function loss or immunogenic patient responses. Two strategies are currently used to reduce aggregation: (1) finding a suitable formulation, which is labor-intensive and requires large protein quantities, or (2) engineering the protein, which requires extensive knowledge about the protein aggregation pathway.
We present a biophysical characterization of the oligomerization and aggregation processes by Interferon alpha-2a (IFNα-2a), a protein drug with antiviral and immunomodulatory properties. This study combines experimental high throughput screening with detailed investigations by small-angle X-ray scattering and analytical ultracentrifugation.
Metropolis Monte Carlo simulations are used to gain insight into the underlying intermolecular interactions. IFNα-2a forms soluble oligomers that are controlled by a fast pH and concentration-dependent equilibrium. Close to the isoelectric point of 6, IFNα-2a forms insoluble aggregates which can be prevented by adding salt.
We show that monomer attraction is driven mainly by molecular anisotropic dipole-dipole interactions that increase with increasing pH. Repulsion is due to monopole-monopole interactions and depends on the charge of IFNα-2a. The study highlights how combining multiple methods helps to systematically dissect the molecular mechanisms driving oligomer formation and to design ultimately efficient strategies for preventing detrimental protein aggregation.
Language: | English |
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Publisher: | American Chemical Society |
Year: | 2021 |
Pages: | 13657-13669 |
ISSN: | 15205207 and 15206106 |
Types: | Journal article |
DOI: | 10.1021/acs.jpcb.1c07090 |
ORCIDs: | 0000-0001-6193-4016 , 0000-0002-9670-7232 , Indrakumar, Sowmya , Peters, Günther H. J. , 0000-0001-8178-8175 and Harris, Pernille |