Precision Characterization of Site-specific O-Acetylated Sialic Acids on N-Glycoproteins

O-Acetylation is a common modification of sialic acid, playing a significant role in glycoprotein stability, immune response, and cell development. The lack of efficient methods for direct analysis of O-acetylated sialoglycopeptides (O-AcSGPs) made the majority of identified O-acetylated sialic acids (O-AcSia) till now had no glycosite/glycoprotein information. Herein, we introduced a new workflow for precise interpretation of O-AcSGPs with probability estimation by recognizing the characteristic B and Y ions of O-AcSias.