神经细胞粘附分子（NCAM）上多胺基糖酸（PolySia）的过度表达促进了过度唾液酸化，从而有利于癌细胞的迁移和侵袭。据认为，为了阻断过度唾液酸化的影响，需要抑制多胺基糖酸转移酶结构域（PSTD）与CMP-Sia的结合。本研究在分子间相互作用特征的基础上，确认了CMP在CMP-Sia和三胺基糖酸三聚体（TriSia）存在时对多胺基糖酸转移酶（PolySTs）具有竞争性抑制作用。进一步的核磁共振分析提示，当CMP-Sia与PolySia共存于溶液中时，多胺基糖酸化可以被部分抑制。此外，令人意外的发现是CMP-Sia在减少PSTD上聚集的多胺基糖酸链的程度方面发挥了作用，可能益于多胺基糖酸化的抑制。本研究的发现可以为癌症治疗药物和抑制剂的最优设计提供新的见解。

The overexpression of polysialic acid (polySia) on neural cell adhesion molecules (NCAM) promotes hypersialylation, and thus benefits cancer cell migration and invasion. It has been proposed that the binding between the polysialyltransferase domain (PSTD) and CMP-Sia needs to be inhibited in order to block the effects of hypersialylation. In this study, CMP was confirmed to be a competitive inhibitor of polysialyltransferases (polySTs) in the presence of CMP-Sia and triSia (oligosialic acid trimer) based on the interactional features between molecules. The further NMR analysis suggested that polysialylation could be partially inhibited when CMP-Sia and polySia co-exist in solution. In addition, an unexpecting finding is that CMP-Sia plays a role in reducing the gathering extent of polySia chains on the PSTD, and may benefit for the inhibition of polysialylation. The findings in this study may provide new insight into the optimal design of the drug and inhibitor for cancer treatment.