Understanding the relationship between biotherapeutic protein stability and solid-liquid interfacial shear in constant region mutants of IgG1 and IgG4.
Bottom Line: Results suggest that the techniques are orthogonal, with thermal methods based on intramolecular interaction and shear device stability based on localized unfolding revealing less stable regions that drive aggregation.Molecular modeling shows the modifications' effects on the antibody structures and indicates a possible role for Fc conformation and Fab-Fc docking in determining suspended protein stability.The data introduce the PDC value as an orthogonal stability indicator, complementary to traditional thermal methods, allowing lead antibody selection based on a more full understanding of process stability.
Affiliation: The Advanced Centre for Biochemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK; MedImmune, Granta Park, Cambridge, CB21 6GH, UK.Show MeSH
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Mentions: The DSC profiles (Fig. 4) showed the antibodies have two clearly resolved transitions, each peak in the trace giving a Tm value for the unfolding of each protein domain. The first peak (Tm1) representing the unfolding transition of the CH2 domain was well resolved for most of the antibody candidates. The Fab and CH3 were unresolved in the second unfolding transition (Tm2) with a higher enthalpy than in Tm1, possibly indicating stronger interactions between subdomains in this region.46 As expected, the modifications in the CH2 change the Tm1 value significantly.
Affiliation: The Advanced Centre for Biochemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK; MedImmune, Granta Park, Cambridge, CB21 6GH, UK.