Details

Autor(en) / Beteiligte

• Forder, James K.
• Palakollu, Veerabhadraiah
• Adhikari, Sudeep
• Blanco, Marco A.
• Derebe, Mehabaw Getahun
• Ferguson, Heidi M.
• Luthra, Suman A.
• Munsell, Erik V.
• Roberts, Christopher J.

Titel

Electrostatically Mediated Attractive Self-Interactions and Reversible Self-Association of Fc-Fusion Proteins

Ist Teil von

• Molecular pharmaceutics, 2024-03, Vol.21 (3), p.1321-1333

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2024

Quelle

MEDLINE

Beschreibungen/Notizen

• Attractive self-interactions and reversible self-association are implicated in many problematic solution behaviors for therapeutic proteins, such as irreversible aggregation, elevated viscosity, phase separation, and opalescence. Protein self-interactions and reversible oligomerization of two Fc-fusion proteins (monovalent and bivalent) and the corresponding fusion partner protein were characterized experimentally with static and dynamic light scattering as a function of pH (5 and 6.5) and ionic strength (10 mM to at least 300 mM). The fusion partner protein and monovalent Fc-fusion each displayed net attractive electrostatic self-interactions at pH 6.5 and net repulsive electrostatic self-interactions at pH 5. Solutions of the bivalent Fc-fusion contained higher molecular weight species that prevented quantification of typical interaction parameters (B 22 and k D). All three of the proteins displayed reversible self-association at pH 6.5, where oligomers dissociated with increased ionic strength. Coarse-grained molecular simulations were used to model the self-interactions measured experimentally, assess net self-interactions for the bivalent Fc-fusion, and probe the specific electrostatic interactions between charged amino acids that were involved in attractive electrostatic self-interactions. Mayer-weighted pairwise electrostatic energies from the simulations suggested that attractive electrostatic self-interactions at pH 6.5 for the two Fc-fusion proteins were due to cross-domain interactions between the fusion partner domain(s) and the Fc domain.