Bioorthogonal Chemistry: Synthesis of Protein-Polymer Conjugates and Orthogonally Crosslinked Protein

Abstract

Bioorthogonal chemistry focuses on the study of chemical reactions that take place in living systems without interfering with native biological systems. These studies often answer different questions of interest among chemical biologists and organic chemist. The central theme of this dissertation is the development and application of bioorthogonal chemistry for site-specific modification of proteins for biocatalysis and protein stabilization. The amber codon suppression technique was used to incorporate the alkene-containing amino acid into proteins. These alkene-encoded proteins will participate in photoclick chemistry or photo-crosslinking reaction for conjugation with their reaction partners. Chapter 1 reviews current bioorthogonal chemistry, with emphasis on the development and optimization of bioorthogonal reactions for protein labeling. Chapter 2 focuses on the development of bottle brush copolymer-enzyme conjugates for potential use in biocatalytic cyclopropanation. Because enzymes generally have a low tolerance for organic cosolvents, we hypothesize that the polymer-enzyme conjugates will show improved protein stability in aqueous media containing organic co-solvents. Chapter 3 focuses on the protein cyclizations via bioorthogonal reactions. Chapter 4 describes a new method of forming an intramolecular covalent bond within protein structure to stabilize proteins in the reducing environment.