Site-Specific Analysis of Core and Antenna Fucosylation on Serum Glycoproteins

Fucosylation is an important structural
feature of glycans and
plays an essential role in the regulation of glycoprotein functions.
Fucosylation can be classified into core- (CF) and antenna-fucosylation
(AF, also known as (sialyl-) Lewis) based on the location on N-glycans, and they perform distinct biological functions.
In this study, core- and antenna-fucosylated N-glycans
on human serum glycoproteins that hold great clinical application
values were systematically characterized at the site-specific level
using StrucGP combined with the recently developed fucosylation assignment
method. The results showed that fucosylation was widely distributed
on serum glycoproteins, with 50% of fucosylated glycopeptides modified
by AF N-glycans, 37% by CF N-glycans,
and 13% by dual-fucosylated N-glycans. Interestingly,
CF and AF N-glycans preferred to modify different
groups of serum glycoproteins with different tissue origins and were
involved in distinctive biological processes. Specifically, AF N-glycoproteins are mainly from the liver and participated
in complement activation, blood coagulation, and endopeptidase activities,
while CF N-glycoproteins originate from diverse tissues
and are mainly involved in cell adhesion and signaling transduction.
These data further enhanced our understanding of fucosylation on circulation
glycoproteins.