Submicron Aggregation of Chemically Denatured Monoclonal Antibody

Area of Science:

• Biochemistry
• Protein Chemistry
• Pharmaceutical Science

Background:

• Isothermal chemical denaturation (ICD) assesses therapeutic protein stability.
• Antibody unfolding pathways and aggregation mechanisms remain unclear.

Purpose of the Study:

• Investigate ICD-induced aggregation in a pharmaceutical monoclonal antibody.
• Understand the nucleation-controlled aggregation mechanism.
• Evaluate the impact of pH on aggregation post-denaturation.

Main Methods:

• Dynamic light scattering to monitor aggregate formation and growth.
• Systematic study of antibody aggregation under varying buffer conditions.
• ICD followed by dilution or dialysis to induce post-denaturation aggregation.

Main Results:

• Identified nucleation-controlled submicron aggregation of the antibody.
• Demonstrated that protein aggregation is triggered after reaching a steady state of unfolding.
• Showcased the influence of pH on the aggregation of stressed proteins after denaturant removal.

Conclusions:

• ICD-dilution is a practical method for studying unfolded protein aggregation propensity.
• This technique allows controlled protein unfolding and initiation of post-ICD aggregation.
• Provides insights into monoclonal antibody aggregation under different formulation conditions.