Egg with PEG–A Lysozyme Based Experiment to Teach Protein Modification and Gel Electrophoresis to Chemistry Undergraduates

Part of the journey to excellence in any discipline is learning how to apply theory and understanding to a wide range of applications. In this article, we present a cross-disciplinary laboratory experiment designed to expose second year undergraduate chemists to the principles of protein modification and gel electrophoresis. This 6 h experiment, tested across two years, enlightens chemistry students to the working practices of biochemists/chemical biologists through the PEGylation of cysteine residues within lysozyme. PEG-maleimide in two different sizes is used to modify lysozyme following incremental reduction by tris(2-carboxyethyl) phosphine. Variation in reducing agent concentration, PEG chain length, and presence of denaturant in reaction buffer provided a range of interesting results and highlights several learning outcomes. The experiment design broadens and reinforces chemistry student’s skillsets by discovering SDS-PAGE gel preparation and analysis, while relating other areas of theoretical and practical chemistry to a bioconjugation based study.