Exploring the Effects of Polymer Functionality on the Activity and Stability of Lysozyme and Cellulase Conjugates

EXPLORING THE EFFECTS OF POLYMER FUNCTIONALITY ON THE ACTIVITY AND STABILITY OF LYSOZYME AND CELLULASE CONJUGATES by Melissa Eileen Dougherty Biomacromolecules made by covalent attachment of polymers to the surfaces of proteins are an interesting area of research with significant applications in drug therapies and growing interest in energy and nanotechnology. Protein-polymer conjugates are typically synthesized by either the grafting-to or grafting-from approach. In grafting-to, polymer is separately synthesized and characterized prior to linkage to the protein. However, in grafting-from, an initiating group is attached to the protein, which allows for growth of the polymer directly from the protein surface. Herein, a hybrid approach is used, combining the advantages of both conjugation techniques. RAFT polymerization is used to grow water soluble polymers for grafting-to and subsequent chain extension from enzymes of interest. First, conjugates made from the well-studied, model enzyme lysozyme are discussed. Next, cellulase-polymer conjugates with potential applications in biofuel production are explored. In these studies, the impact of polymer size and functional groups on enzymatic activity, thermal and chemical stability are investigated. Important trends gleaned from this work contribute to the understanding of structure-property correlations in protein-polymer conjugates. These relationships are critical to the advancement of protein-polymer conjugates in efforts to produce engineered biomacromolecules with tunable behaviors for specific applications. EXPLORING THE EFFECTS OF POLYMER FUNCTIONALITY ON THE ACTIVITY AND STABILITY OF LYSOZYME AND CELLULASE CONJUGATES