Anomeric Fatty Acid Functionalization Prevents Nonenzymatic <i>S</i>-Glycosylation by Monosaccharide Metabolic Chemical Reporters
Nichole J. Pedowitz, Emma G. Jackson, Justin M. Overhulse, Charles E. McKenna, Jennifer J. Kohler, Matthew R. Pratt
Abstract
Metabolic chemical reports have fundamentally changed the way researchers study glycosylation. However, when administered as per-O-acetylated sugars, reporter molecules can participate in nonspecific chemical labeling of cysteine residues termed S-glycosylation. Without detailed proteomic analyses, these labeling events can be indistinguishable from bona fide enzymatic labeling convoluting experimental results. Here, we report a solution in the synthesis and characterization of two reporter molecules functionalized at the anomeric position with hexanoic acid: 1-Hex-GlcNAlk and 1-Hex-6AzGlcNAc. Both reporters exhibit robust labeling over background with negligible amounts of nonspecific chemical labeling in cell lysates. This strategy serves as a template for the design of future reporter molecules allowing for more reliable interpretation of results.