On the hydrodynamic properties of IgG1 glycoforms in comparison with pure protein and pure carbohydrate assemblies

Abstract

Biological macromolecules are routinely exposed to various stresses during production, processing, transport and storage. Inadvertently, this may ultimately result in protein inactivation, denaturation and aggregation. The objective of the present study was to investigate the stability or instability which can occur fo llowing routine bio-processing of phannaceutical and other protein preparations with different levels of glycosylation, in addition to two polysaccharide samples of significant importance to the food industry. Using hydrodynamic techniques, the effects of physico-chemical factors on the stability of macromolecules, including three phannaceutical fannulations (monoclonal antibodies), was investigated via accelerated degradation or structural modifications. Besides glycosylation, the influence of various other parameters such as concentration, pH, storage temperature and structural modifications were examined. Deglycosylation of antibodies resulted in changes in intrinsic molecular properties such as sedimentation velocity and intrinsic viscosity with overall impact on stability. Both the maxi- and mini-ferritins follow a similar dissociation/reassembly pathway, the knowledge of which may be helpful in the engineering of similar molecules with applications in the pharmaceutical and medical fields. In-vitro mutagenesis in POR causes changes in structural flexibility and correlates to major differences in the formation of stabilized ternary complexes suggesting conformational changes, which is relevant to its structure and catalytic activity. Finally, characterisation of two polysaccharide gum samples showed significant differences in tenns of polydispersity, solution viscosity and molecular weight distribution compared to the protein and glycoprotein samples above. Intrinsic viscosity estimates differed from those of similar molecules with potential for industrial applications. Hydrodynamics techniques are invaluable for structural characterisation of macromolecular solutions.EThOS - Electronic Theses Online ServiceGBUnited Kingdo