Understanding the relationship between biotherapeutic protein stability and solid-liquid interfacial shear in constant region mutants of IgG1 and IgG4.
Bottom Line: Five variants of IgG1 and IgG4 antibodies were created using combinations of two discrete triple amino acid sequence mutations denoted TM and YTE.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
Related in: MedlinePlus
Mentions: Molecular models of the IgG1 Fc and hinge region, with two internal fucosylations, were analyzed for their SAP and electrostatic surface charge displayed in Figure 8. There are known docking postures of the Fab onto the hinge and the superior surface of the Fc. The CH1-1 loop of the Fab is more intrinsically disordered than even vhCDR352 and is oriented toward the central hinge in the full-length mAb crystal structure,53 though it does not have electron density in the model 1HZH (PDB). This, together with high sequence variability in this loop, would imply that it has no conserved interactions with the hinge region. The minor hinge, however, has greater sequence conservation and is shown in a stably docked posture in the full-length antibody crystal structure,53 orientated with the minor hinge of the light chain forming an interface with the location of the first two mutants of the “TM”.
Affiliation: The Advanced Centre for Biochemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK; MedImmune, Granta Park, Cambridge, CB21 6GH, UK.