Intact N-glycopeptide analysis of human platelets reveals a Glycostructure important for platelet function

Area of Science:

• Hematology
• Glycobiology
• Proteomics

Background:

• Platelet glycosylation significantly impacts platelet function.
• Understanding specific glycoforms' roles in platelet activity requires further investigation.

Purpose of the Study:

• To globally analyze intact N-glycopeptides in human platelets.
• To map platelet glycopeptides, glycosites, and glycans.
• To investigate the functional role of specific glycoforms, particularly Lewis y, in platelet adhesion.

Main Methods:

• Enrichment of glycopeptides using ZIC-hydrophilic interaction chromatography.
• Analysis of glycopeptides via Liquid Chromatography-Tandem Mass Spectrometry.
• Verification of Lewis y structures using immunoprecipitation assays and functional evaluation through platelet adhesion assays.

Main Results:

• Identification of 1,425 intact N-glycopeptides from 190 N-glycoproteins and 358 glycans on 328 glycosites.
• Glycoproteins identified are primarily involved in platelet adhesion pathways.
• Lewis y structures were found on von Willebrand factor, thrombospondin 1, and glycoprotein V, and their blockade decreased platelet adhesion to collagen I.

Conclusions:

• This study provides a comprehensive map of N-glycopeptides in human platelets.
• Lewis y is identified as a functional glycoantigen on platelets, playing a role in platelet-collagen adhesion.
• Targeting Lewis y may offer a novel approach to modulate platelet function in adhesion-related processes.