Analysis of IgA1 N-glycosylation and its contribution to FcalphaRI binding.
Biochemistry
; 47(43): 11285-99, 2008 Oct 28.
Article
em En
| MEDLINE
| ID: mdl-18826328
ABSTRACT
The IgA isotype of human antibodies triggers inflammatory responses via the IgA-specific receptor FcalphaRI (CD89). Structural studies have suggested that IgA1 N-glycans could modulate the interaction with FcalphaRI. We have carried out detailed biophysical analyses of three IgA1 samples purified from human serum and recombinant IgA1-Fc and compared their binding to FcalphaRI. Analytical ultracentrifugation revealed wide variation in the distribution of polymeric species between IgA1 samples, and Fourier transform ion cyclotron resonance mass spectrometry showed overlapping but distinct populations of N-glycan species between IgA1 samples. Kinetic and equilibrium data from surface plasmon resonance experiments revealed that variation in the IgA1 C H2 N-glycans had no effect on the kinetics or affinity constants for binding to FcalphaRI. Indeed, complete enzymatic removal of the IgA1 N-glycans yielded superimposable binding curves. These findings have implications for renal diseases such as IgA nephropathy.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Imunoglobulina A
/
Receptores Fc
/
Antígenos CD
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article