X-ray Scattering and Coarse-Grained Simulations for Clustering and Interactions of Monoclonal Antibodies at High Concentrations

Journal Article · 30 May 2019 · Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry

DOI: https://doi.org/10.1021/acs.jpcb.9b04478 · OSTI ID:1562476

Dear, Barton J. ^[1]; Bollinger, Jonathan A. ^[2]; Chowdhury, Amjad  ^[1]; Hung, Jessica J. ^[1]; Wilks, Logan R. ^[1]; Karouta, Carl A. ^[1]; Ramachandran, Kishan ^[1]; Shay, Tony Y. ^[1]; Nieto, Maria P. ^[1]; Sharma, Ayush ^[1]; Cheung, Jason K. ^[3]; Nykypanchuk, Dmytro ^[4]; Godfrin, P. Douglas  ^[5]; Johnston, Keith P.  ^[1]; Truskett, Thomas M.  ^[1]

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1. The Univ. of Texas at Austin, Austin, TX (United States)
2. The Univ. of Texas at Austin, Austin, TX (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
3. Merck & Co., Inc., Kenilworth, NJ (United States)
4. Brookhaven National Lab. (BNL), Upton, NY (United States)
5. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Attractive protein-protein interactions (PPI) in concentrated monoclonal antibody (mAb) solutions may lead to reversible oligomers (clusters) that impact colloidal stability and viscosity. Herein, the PPI are tuned for two mAbs via the addition of arginine (Arg), NaCl, or ZnSO₄ as characterized by the structure factor (S_eff(q)) with small angle x-ray scattering (SAXS). The SAXS data are fit with molecular dynamics simulations by placing a physically relevant short-ranged attractive interaction on selected beads in coarse-grained 12 bead models of the mAb shape. The optimized 12-bead models are then used to differentiate key microstructural properties, including center of mass radial distribution functions (g_COM(r)), coordination numbers and cluster size distributions (CSD). The addition of co-solutes results in more attractive Seff(q) relative to the no co-solute control for all systems tested, with the most attractive systems showing an upturn at low q. Only the All1 model with an attractive site in each Fab and Fc region (possessing Fab-Fab, Fab-Fc and Fc-Fc interactions) can reproduce this upturn, and the corresponding CSDs show the presence of larger clusters compared to the control. In general, for models with similar net attractions, i.e., second osmotic virial coefficients, the size of the clusters increases as the attraction is concentrated on a smaller number of evenly distributed beads. Here, the cluster size distributions from simulations are used to improve the understanding and prediction of experimental viscosities. The ability to discriminate between models with bead interactions at particular Fab and Fc bead sites from SAXS simulations, and to provide real space properties (CSD and g_COM(r)), will be of interest in engineering protein sequence and formulating protein solutions for weak PPI to minimize aggregation and viscosities.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0012704
• OSTI ID: 1562476
• Report Number(s): BNL-212084-2019-JAAM; TRN: US2000716
• Journal Information: Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry, Vol. 123, Issue 25; ISSN 1520-6106
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English