Additive-based protein stabilization for stress-prone and unstable proteins

Protein-stabilizing additives have traditionally been investigated under dilute solution conditions using simple monomeric proteins as model systems. While such studies have clarified fundamental additive–protein interactions, their direct applicability to practical research and industrial contexts remains limited. This review leverages insights from model systems to summarize additive-based stabilization strategies in two major directions. First, we address process-related stresses, focusing on high-concentration conditions and interfacial stress frequently encountered during protein handling. Second, we highlight strategies for protein classes that are challenging to stabilize or purify, including membrane proteins, viral spike proteins, and intrinsically disordered proteins. This review aims to encourage additive use when proteins are difficult to stabilize under challenging conditions. • Most additive studies rely on dilute, folded model proteins with limited applicability • We review stabilization strategies beyond model systems in three critical contexts • High-concentration formulations: viscosity, aggregation, and phase separation issues • Process-related stresses: concentration steps, freeze–thaw, and interfacial instability • Structurally complex proteins: membrane proteins, viral spike glycoproteins, and IDPs