(467e) Elucidating the Distinct Unfolding Pathways of Bovine Serum Albumin Under Varying External Stressors: A Comprehensive Molecular Dynamics Simulation Study

The therapeutic potential of proteins has revolutionized the field of biopharmaceuticals, with the ability to treat a wide range of diseases, including cancer. However, the effectiveness of these biologics is often hampered by their sensitivity to environmental changes and their delicate nature. The destabilization or unfolding of proteins caused by various external stressors such as pH, temperature, and shear forces during production, transportation, and administration compromises their functionality and therapeutic effectiveness. Therefore, engineering proteins for increased stability is essential, necessitating a detailed understanding of how proteins behave under different stressors and identifying critical weak areas within the proteins that need reinforcement for stability.

In this study, all-atom molecular dynamics simulations are performed to unravel the unfolding process of Bovine Serum Albumin (BSA) in response to various external stressors, such as temperature, pH, and shear stress. We assess the protein's structural alterations during denaturation using multiple metrics, including root-mean-square deviation (RMSD), number of hydrogen bonds, and solvent-accessible surface area (SASA). To further elucidate the progressive order of destabilization, we track the structural evolution of BSA by mapping to its domains. Notably, we observe distinct patterns of destabilization across different conditions, with high temperatures leading to a gradual structural change throughout the whole protein. The acidic pH affects the protein structure at a localized level by primarily causing domains I and III to move apart without altering a large portion of the secondary structure. In contrast, the shear stress distorts the protein structure differently, mainly initiating from domain III. These findings illuminate the different pathways through which environmental stressors induce protein denaturation, emphasizing the necessity of customized design to improve protein stability under different conditions. Future work includes potential strategies, namely polymer-protein hybrids, to enhance the stability of therapeutic proteins.