Effect of PEG molecular weight and PEGylation degree on the physical stability of PEGylated lysozyme

Publication date: 15 March 2017 Source:International Journal of Pharmaceutics, Volume 519, Issues 1–2 Author(s): Josefine Morgenstern, Pascal Baumann, Carina Brunner, Jürgen Hubbuch During production, purification, formulation, and storage proteins for pharmaceutical or biotechnological applications face solution conditions that are unfavorable for their stability. Such harmful conditions include extreme pH changes, high ionic strengths or elevated temperatures. The characterization of the main influencing factors promoting undesired changes of protein conformation and aggregation, as well as the manipulation and selective control of protein stabilities are crucially important to biopharmaceutical research and process development. In this context PEGylation, i.e. the covalent attachment of polyethylene glycol (PEG) to proteins, represents a valuable strategy to improve the physico-chemical properties of proteins. In this work, the influence of PEG molecular weight and PEGylation degree on the physical stability of PEGylated lysozyme is investigated. Specifically, conformational and colloidal properties were studied by means of high-throughput melting point determination and automated generation of protein phase diagrams, respectively. Lysozyme from chicken egg-white as a model protein was randomly conjugated to 2kDa, 5kDa and 10kDa mPEG-aldehyde and resulting PEGamer species were purified by chromatographic separation. Besides protein stability assessment, residual e...
Source: International Journal of Pharmaceutics - Category: Drugs & Pharmacology Source Type: research