Crystal structure of an anti-podoplanin antibody bound to a disialylated O-linked glycopeptide

https://doi.org/10.1016/j.bbrc.2020.08.103Get rights and content
Under a Creative Commons license
open access

Highlights

  • Podoplanin is a highly O-linked glycoprotein utilized as a biomarker.

  • The antibody recognizing the peptides attached sialylated glycan has been generated.

  • The disialyl-core-l linked glycopeptide was synthesized for the first time.

  • The first 3D structure of an antibody bound the disialylated peptide was determined.

  • This structure reveals the advantage of antibodies to recognize extensive epitopes.

Abstract

Podoplanin (PDPN) is a highly O-glycosylated glycoprotein that is utilized as a specific lymphatic endothelial marker under pathophysiological conditions. We previously developed an anti-human PDPN (hPDPN) monoclonal antibody (mAb), clone LpMab-3, which recognizes the epitope, including both the peptides and the attached disialy-core-l (NeuAcα2-3Galβl-3 [NeuAcα2-6]GalNAcαl-O-Thr) structure at the Thr76 residue in hPDPN. However, it is unclear if the mAb binds directly to both the peptides and glycans. In this study, we synthesized the binding epitope region of LpMab-3 that includes the peptide (-67LVATSVNSV-T-GIRIEDLP84-) possessing a disialyl-core-1 O-glycan at Thr76, and we determined the crystal structure of the LpMab-3 Fab fragment that was bound to the synthesized glycopeptide at a 2.8 Å resolution. The six amino acid residues and two sialic acid residues are directly associated with four complementarity-determining regions (CDRs; H1, H2, H3, and L3) and four CDRs (H2, H3, L1, and L3), respectively. These results suggest that IgG is advantageous for generating binders against spacious epitopes such as glycoconjugates.

Keywords

Podoplanin (PDPN)
Monoclonal antibody
Crystal structure
Glycopeptide

Cited by (0)