Nano Differential Scanning Fluorimetry-Based Thermal Stability Screening and Optimal Buffer Selection for...

Area of Science:

• Biochemistry
• Protein Science
• Formulation Development

Background:

• Protein stability is critical for therapeutic efficacy.
• High-throughput screening methods are needed for optimal formulation.
• Immunoglobulin G (IgG) requires careful buffer selection to maintain stability.

Purpose of the Study:

• To evaluate IgG thermal stability and aggregation in different buffer systems.
• To identify optimal buffer conditions for IgG formulation using nanoDSF.
• To compare aggregation behavior in sodium acetate, citrate, and phosphate buffers.

Main Methods:

• Nano differential scanning fluorimetry (nanoDSF) for thermal unfolding and aggregation analysis.
• Dynamic light scattering (DLS) to study protein-protein interactions.
• Investigation across a pH range (4-8) in three distinct buffer types.

Main Results:

• IgG thermal unfolding temperature (Tm) increased with pH across all buffers.
• Sodium acetate buffer at pH < 4.6 demonstrated superior anti-aggregation properties.
• Citrate buffer induced higher aggregation and viscosity compared to acetate buffer at equivalent pH.
• DLS indicated attractive intermolecular interactions in citrate and repulsive in acetate buffers.

Conclusions:

• Sodium acetate buffer at pH 4.6 is recommended for IgG formulation.
• NanoDSF is a valuable tool for antibody formulation development and buffer optimization.
• Buffer species significantly impacts IgG aggregation propensity and protein-protein interactions.