Protein Native-State Stabilization by Placing Aromatic Side Chains in N-Glycosylated Reverse Turns

• DOI: 10.1126/science.1198461
• Publication Date: 2011-02-03T19:31:16Z
• Authors: Elizabeth K. Culyba; Joshua L. Price; Sarah R. Hanson; Apratim Dhar; Chi-Huey Wong; Martin Gruebele; Evan T. Powers; Jeffery W. Kelly
• Keywords: Side chain

N-glycosylation of eukaryotic proteins helps them fold and traverse the cellular secretory pathway can increase their stability, although molecular basis for stabilization is poorly understood. Glycosylation at naïve sites (ones that normally are not glycosylated) could be useful therapeutic research applications but currently results in unpredictable changes to protein stability. We show placing a phenylalanine residue two or three positions before glycosylated asparagine distinct reverse turns facilitates stabilizing interactions between aromatic side chain first N-acetylglucosamine glycan. Glycosylating this portable structural module, an enhanced sequon, different stabilizes native states by -0.7 -2.0 kilocalories per mole increases glycosylation efficiency.