NMR assignments of the N-glycans of the Fc fragment of mouse immunoglobulin G2b glycoprotein.
Biomol NMR Assign
; 15(1): 187-192, 2021 04.
Article
in En
| MEDLINE
| ID: mdl-33423189
ABSTRACT
The Fc portion of immunoglobulin G (IgG) promotes defensive effector functions in the immune system by interacting with Fcγ receptors and complement component C1q. These interactions critically depend on N-glycosylation at Asn297 of each CH2 domain, where biantennary complex-type oligosaccharides contain microheterogeneities resulting primarily from the presence or absence of non-reducing terminal galactose residues. Crystal structures of Fc have shown that a pair of N-glycans is located between the two CH2 domains. Here we applied our metabolic isotope labeling technique using mammalian cells for in-solution structural characterization of mouse IgG2b-Fc glycoforms with a molecular mass of 54 kDa. Based on spectral assignments of the N-glycans as well as polypeptide backbones of Fc, we probed conformational perturbations of Fc induced by N-glycan trimming, especially enzymatic degalactosylation. The results indicated that degalactosylation structurally perturbed the Fc region through rearrangement of glycan-protein interactions. The spectral assignments of IgG2b-Fc glycoprotein will provide the basis for NMR investigation of its dynamic conformations and interactions with effector molecules in solution.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Immunoglobulin Fc Fragments
/
Nuclear Magnetic Resonance, Biomolecular
Language:
En
Journal:
Biomol NMR Assign
Journal subject:
BIOLOGIA MOLECULAR
/
MEDICINA NUCLEAR
Year:
2021
Document type:
Article
Affiliation country: