Glycoproteomics analysis reveals differential site-specific N-glycosylation of donkey milk fat globule membrane protein during lactation. (15th February 2023)

• Record Type: Journal Article
• Authors: Guan, Boyuan; Chai, Yuxia; Amantai, Xiakouna; Liu, Xiaoyu; Chen, Xinping; Cao, Xueyan; Yue, Xiqing; Liu, Biao
• Is Part Of: Food chemistry. Volume 402(2023)
• Publication Date: 2023-02-15
• Subjects: Donkey milk -- Colostrum -- Mature milk -- Milk fat globule membrane N-glycoprotein -- Site-specific N-glycosylation -- Glycoproteomics; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2022.134266
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Donkey MFGM protein site-specific N-glycosylation differs during lactation. 1787 N-glycopeptides of 380 donkey MFGM proteins were identified during lactation. Donkey MFGM protein's N-glycosylation macro- and microheterogeneity were outlined. 52 N-glycopeptides of 23 donkey MFGM proteins differ significantly over lactation. Structure-activity relationship of donkey MFGM N-glycoproteins were elucidated. Abstract: N-glycosylation is a prevalent and complex post-translational modification of milk proteins with significant biological importance. However, the systematic characterisation of donkey milk fat globule membrane (MFGM) N-glycoproteins remains largely ill-defined. Here, 1443 intact N-glycopeptides from 336 MFGM glycoproteins in donkey colostrum (DC) and 489 intact N-glycopeptides from 86 MFGM glycoproteins in donkey mature milk (DM) were identified via label-free site-specific glycoproteomics. Mannosylation and fucosylation were predominant in DC MFGM N-glycoproteins compared to sialylation and mannosylation in DM. Among them, 22 site-specific N-glycans attached to 14 glycosites of eight glycoproteins were significantly increased, whereas 30 site-specific N-glycans attached to 19 glycosites of 16 glycoproteins were significantly decreased. Furthermore, the site-specific N-glycans with Neu5Gc moieties or simultaneous fucosylation and sialylation were not significantly increased, exhibiting significant site specificity. We provide new insights into the composition of donkey MFGM N-glycoproteins and their roles in donkey milk-related biological functions.