O-acetylation is a common modification of sialic acids that has been implicated in a multitude of biological and disease processes. A lack of analytical methods that can determine exact structures of sialic acid variants is a hurdle to determine roles of distinct O-acetylated sialosides. Here, we describe a drift tube ion mobility-mass spectrometry approach that can elucidate exact O-acetylation patterns as well as glycosidic linkage types of sialosides isolated from complex biological samples. It is based on the use of a library of synthetic O-acetylated sialosides to establish intrinsic collision cross section (CCS) values of diagnostic fragment ions. The CCS values were used to characterize O-acetylated sialosides from mucins and N-linked glycans from biologicals as well as equine tracheal and nasal tissues. It uncovered contrasting sialic acid linkage types of acetylated and non-acetylated sialic acids and provided a rationale for sialic acid binding preferences of equine H7 influenza A viruses.

O-乙酰化是唾液酸的一种常见修饰，与多种生物和疾病过程有关。缺乏能够确定唾液酸变体精确结构的分析方法是确定不同O-乙酰化唾液酸苷作用的障碍。在这里，我们描述了一种漂移管离子淌度质谱方法，可以阐明从复杂生物样品中分离出的唾液酸的精确O-乙酰化模式以及糖苷键类型。它基于使用合成O-乙酰化唾液酸苷库来建立诊断碎片离子的固有碰撞截面 (CCS) 值。CCS 值用于表征来自生物制品以及马气管和鼻组织的粘蛋白的O-乙酰化唾液酸和N-连接聚糖。它揭示了乙酰化和非乙酰化唾液酸的对比唾液酸连接类型，并为马 H7 甲型流感病毒的唾液酸结合偏好提供了基本原理。