Development of optimized conditions for Glaser-Hay bioconjugations.

The efficient preparation of protein bioconjugates represents a route to novel materials, diagnostics, and therapeutics. We previously reported a novel bioorthogonal Glaser-Hay reaction for the preparation of covalent linkages between proteins and a reaction partner; however, deleterious protein degradation was observed under extended reaction conditions. Herein, we describe the systematic optimization of the reaction to increase coupling efficiency and decrease protein degradation. Two optimized conditions were identified varying either the pH of the reaction or the bidentate ligand employed, allowing for more rapid conjugations and/or less protein oxidation.