Analytical Challenges Assessing Protein Aggregation and Fragmentation Under Physiologic Conditions

Effect of Aggregation and Molecular Size on the Ice Nucleation Efficiency of Proteins

“…Fragmentation is caused by a disruption in a covalent bond and may occur spontaneously through hydrolysis of susceptible amino acids, such as aspartic acid and tryptophan. , Fragmentation susceptibility in solution occurs as a result of the flexibility of the tertiary structure backbone and side chains of amino acids, resulting in peptide bond cleavage . Solvent conditions (extreme pH and temperature) can facilitate cleavage of the protein, which may result in lower ice nucleation efficiency observed for apoferritin at acidic conditions. , Studies have shown that acidity is likely to change the structure of proteins. , Given this fact, changes in aggregation and ice nucleation as a function of pH would be a valuable subject for future work.…”

“… 84 , 85 Fragmentation susceptibility in solution occurs as a result of the flexibility of the tertiary structure backbone and side chains of amino acids, resulting in peptide bond cleavage. 85 Solvent conditions (extreme pH and temperature) can facilitate cleavage of the protein, which may result in lower ice nucleation efficiency observed for apoferritin at acidic conditions. 26 , 84 Studies have shown that acidity is likely to change the structure of proteins.…”

Biosynthesized tumor acidity and MMP dual-responsive plant toxin gelonin for robust cancer therapy

“…After administration via intravenous injection, the exposure of therapeutic proteins to body fluids (such as blood) may affect their stability and efficacy profile. 52 So to test its serum stability, TPpG was incubated with a 10% FBS-containing neutral ( pH 7.4) or acidic ( pH 6.5) cell medium at 37 °C for different time periods and subjected to SDS-PAGE analysis. A clear TPpG band as indicated by the red arrow could be observed in all lanes after incubation in the serum-containing medium of both pHs even after 48 h (Fig.…”

Protein Aggregates in Inhaled Biologics: Challenges and Considerations

“…It is important to note that the guidance for sub-visible particles is not designed to de-risk protein aggregation in vivo or immunogenicity concerns, but rather to avoid the risk of capillary occlusion 27 . Pre-clinical in vitro models are increasingly employed to evaluate the protein stability post injection 28 , 29 , 30 . For instance, a novel protein-free serum in vitro setup revealed faster degradation profiles for two monoclonal antibodies (mabs) compared to accelerated stability studies 30 .…”