posted on 2021-05-14, 20:03authored bySiyao Wang, Simon R. Foster, Julie Sanchez, Leo Corcilius, Mark Larance, Meritxell Canals, Martin J. Stone, Richard J. Payne
Chemokines
are secreted proteins that regulate leukocyte migration
during inflammatory responses by signaling through chemokine receptors.
Full length CC chemokine ligand 14, CCL14(1–74), is a weak
agonist for the chemokine receptor CCR1, but its activity is substantially
enhanced upon proteolytic cleavage to CCL14(9–74). CCL14 is
O-glycosylated at Ser7, adjacent to the site of proteolytic activation.
To determine whether glycosylation regulates the activity of CCL14,
we used native chemical ligation to prepare four homogeneously glycosylated
variants of CCL14(1–74). Each protein was assembled from three
synthetic peptide fragments in “one-pot” using two sequential
ligation reactions. We show that while glycosylation of CCL14(1–74)
did not affect CCR1 binding affinity or potency of activation, sialylated
variants of CCL14(1–74) exhibited reduced activity after treatment
with plasmin compared to nonsialylated forms. These data indicate
that glycosylation may influence the biological activity of CCL14
by regulating its conversion from the full-length to the truncated,
activated form.