Effects of shear on proteins in solution

Abstract

The effects of "shear" on proteins in solution are described and discussed. Research on this topic covers many decades, beginning with investigations of possible denaturation of enzymes during processing, whilst more recent concerns are how the quality of therapeutic proteins might be affected by shear or shear related effects.The paradigm that emerges from most studies is that shear in the fluid mechanical sense is unlikely by itself to damage most proteins and that interfacial phenomena are critically important. In particular, moving gas-liquid interfaces can be very deleterious. Aggregation of therapeutic proteins on nanoparticles shed from solid surfaces is a recent concern because of potential consequences on patient safety. It is clear that labeling such damage as "shear" is a mistake as this inhibits clear investigations of, and thinking about, the true causes of damage to proteins in solution during processing.

Aggregates in monoclonal antibody manufacturing processes

“…As mentioned above, the result may be that the protein experiences a wide range of pH, ionic strength, protein concentrations, and contact materials during the process. In addition to that, it has to be considered that at large scale the protein is exposed to mechanical stresses such as agitation in tanks and pumping (Thomas and Geer, 2011). Once the protein has been purified, it is typically filled into bottles, bags, or cryo-vessels for further freezing and storage.…”

“…During agitation of protein solutions a gas/ liquid interface is created at which aggregation predominantly occurs. There have now been many studies specifically investigating how proteins behave at gas-liquid interfaces (Thomas and Geer, 2011). Mahler et al (2005) claimed that agitation in the presence of a (hydrophobic) gas-liquid interface caused aggregation of immunoglobulin-G1 (IgG1).…”

“…Typically lobular pumps are used to load product onto chromatography units, during viral filtration steps, UF, and during final filling (Gomme et al, 2006a;Thomas and Geer, 2011). It is quite extended the knowledge that these pumping processes expose mAb to mechanical shear forces that might result into aggregates formation because most damage to proteins during processing will increase with higher fluid flow rates, for example, in passage through a pump, however, it has not always been clear that any effects are truly attributable to shear in the fluid mechanical sense, which is caused by velocity gradients in moving liquids (Thomas and Geer, 2011).…”

Inducing protein aggregation by extensional flow

“…The force applied onto a protein as a consequence of hydrodynamic flow has also been observed to trigger protein aggregation and has fundamental (3), medical (4), and industrial relevance, especially in the manufacture of biopharmaceuticals (5)(6)(7)(8). Although a wealth of studies have been performed (7,(9)(10)(11)(12)(13), no consensus has emerged on the ability of hydrodynamic flow to induce protein aggregation (7,14,15). This is due to the wide variety of proteins used (ranging from lysozyme, BSA, and alcohol dehydrogenase to IgGs), differences in the type of flow field generated (e.g., shear, extensional, or mixtures of these), and to the presence or absence of an interface (16).…”

Fractionation of Apis mellifera venom by means of ultrafiltration: removal of phospholipase A 2

“…The low decrease in absorbance for the permeate indicated that phospholipase A 2 did not show the ability to catalyze the hydrolysis of phospholipids. This might be explained due to the denaturation of the enzyme during permeation tests through the membrane, possibly as the result of the interfacial interaction of the macromolecule with the solid irregular pores (Thomas and Geer, 2011). This result is significant, since the permeate can improve product safety.…”