Bilateral Effects of Excipients on Protein Stability: Preferential Interaction Type of Excipient and Surface Aromatic Hydrophobicity of Protein

Abstract

These findings provided strong evidence that excipient possessed bilateral effects, and its application should be determined on different preferential interaction behaviors of excipients with protein, especially with the aromatic hydrophobic region.

Protein Aggregation and Performance Optimization Based on Microconformational Changes of Aromatic Hydrophobic Regions

“…Moreover, the class of tryptophan residue in native protein plays a significant role in the microconformational changes and protein aggregation (Figure 7B). 18 Tryptophan residues of the class I tended to be only exposed in the presence of amine and guanidine compounds, while those of class II/III showed both exposed and buried microconformational changes. GdnHCl or Arg exerted various effects on the microconformational changes of aromatic hydrophobic regions and the aggregation degrees of papain, BSA, HSA, Lyso, Ela, β-Lg, ProK, and OVA (Table 2).…”

“…Solubility determinations were studied based on the method given in our previous research. 18 The transfer free energy of amino acid derivatives from water to the additive solution was calculated from eq 5…”

“…It has been reported that, upon addition of arginine additive, the aromatic hydrophobic regions of bovine serum albumin experienced burial and its aggregation behavior was inhibited, while those of ovalbumin exhibited exposure and aggregation was accelerated. 18 To date, it remains unclear how the protein−additive interaction and protein physicochemical property regulate the microconformational changes of the aromatic hydrophobic regions of proteins. In particular, little is known about the effects of microconformational changes on protein stability and aggregation.…”

“…Interaction with additives can lead to microconformational changes of the aromatic hydrophobic regions in protein molecules. , Dougherty found that amine or guanidine compounds could interact with aromatic amino acids mainly through hydrogen bonds and “cation−π” interaction to which tryptophan residues made a bigger contribution than tyrosine or phenylalanine residues. , However, the microconformational change and the aggregation behavior may differ between proteins with distinct surface aromatic hydrophobicity, i.e., the distinct spatial locations of aromatic amino acids in the protein molecule. It has been reported that, upon addition of arginine additive, the aromatic hydrophobic regions of bovine serum albumin experienced burial and its aggregation behavior was inhibited, while those of ovalbumin exhibited exposure and aggregation was accelerated . To date, it remains unclear how the protein–additive interaction and protein physicochemical property regulate the microconformational changes of the aromatic hydrophobic regions of proteins.…”

Effects of Monovalent Salt on Protein-Protein Interactions of Dilute and Concentrated Monoclonal Antibody Formulations

“…The spatial distances between individual mAb molecules decrease significantly with increasing protein concentration, leading to self-association and elevated solution viscosity [ 7 , 8 , 9 ]. To this end, excipients are frequently included in solution formulations to improve the stability, bioavailability and manufacturability of mAb products [ 10 , 11 , 12 , 13 ].…”