Role of Oligosaccharide Residues of IgG1-Fc in FcγRIIb Binding

Mimura, Yusuke; Sondermann, Peter; Ghirlando, Rodolfo; Lund, John; Young, Stephen P.; Goodall, Margaret; Jefferis, Roy

doi:10.1074/jbc.m107478200

Cited by 226 publications

(165 citation statements)

References 50 publications

Supporting

Mentioning

159

Contrasting

Order By: Relevance

“…It has been reported previously that deglycosylation of IgE has little effect upon receptor binding (11) and that E. coli expressed fragments retain high-affinity receptor binding activity (12). This is in contrast to the behavior of IgG where the loss of carbohydrate from the Fc destroys receptor binding altogether (13). Here we report the first full kinetic characterization of a fully folded, carbohydrate-free IgE Fc subfragment.…”

Section: Immunoglobulin E (Ige)mentioning

confidence: 56%

Disulfide Linkage Controls the Affinity and Stoichiometry of IgE Fcϵ3–4 Binding to FcϵRI

Hunt

Beavil

Calvert

et al. 2005

Journal of Biological Chemistry

View full text Add to dashboard Cite

؊1 , similar to that determined previously for an isolated and partially folded C⑀3 domain, demonstrates that substantial reduction in affinity can be achieved by preventing the engagement of one of the two C⑀3 domains. Recent structural data indicate that conformational change in IgE is required to allow both C⑀3 domains to bind, and thus an allosteric inhibitor that prevents access to the second C⑀3 has the potential to reduce the ability of IgE to sensitize allergic effector cells. Immunoglobulin E (IgE)1 is the antibody class that plays a central role in the allergic response (1). Mast cells and basophils express a high-affinity receptor for IgE, Fc⑀RI, and it is the cross-linking of receptor-bound IgE on these cells by multivalent allergens that triggers the immediate release of preformed inflammatory mediators. The affinity of IgE for Fc⑀RI is uniquely high among Ig-receptor complexes, two to five orders of magnitude higher than that of IgG for its receptors Fc␥ RI-III (2). This is due principally to a very slow off-rate. The half-life of IgE bound to Fc⑀RI is hours (3) compared with only minutes for IgG bound to its receptors (4). Inhibition of IgE binding to Fc⑀RI or at least modulation of its binding kinetics is a potential therapeutic strategy.IgE Fc binds to the receptor with a 1:1 stoichiometry (5) using both Fc heavy chains (6). The crystal structure of the complex between the IgE fragment, Fc⑀3-4 (a homodimer of ⑀-chains consisting of the C⑀3 and C⑀4 domains), and a soluble fragment of the IgE-binding ␣-chain of the receptor, sFc⑀RI␣ (6), revealed the precise details of the involvement of the two C⑀3 domains in the complex. The extensive binding interface consists of two subsites, one contributed by each C⑀3 domain, and thus the maintenance of the dimeric site might be expected to be important for high-affinity binding. The C⑀3 domain also contains an attachment site (Asn-394) for N-linked carbohydrate that is conserved in other antibody classes (e.g. Asn-297 in the C␥2 domain of IgG Fc). Although the crystal structure did not reveal any contact with carbohydrate (6), an indirect effect of glycosylation upon receptor binding via stabilization of the polypeptide conformation cannot be ruled out. Indeed, an isolated C⑀3 domain expressed in Escherichia coli and lacking carbohydrate was found to be only partially folded (7) and NMR analysis of the same fragment indicates that it may have a molten-globule-like structure (8).The aim of this study was to determine the contributions of these two factors, dimerization and glycosylation of the C⑀3 domains, to the kinetics and affinity of Fc⑀RI binding. We have analyzed these effects using four variants of the Fc⑀3-4 fragment: (i) disulfide-linked and glycosylated (Fc⑀3-4); (ii) lacking only the disulfide link (redFc⑀3-4); (iii) lacking only glycosylation (deglyFc⑀3-4); and (iv) lacking both structural features (Fc⑀3-4⌬C). Fc⑀3-4 lacks the C⑀2 domains of the complete IgE Fc, but we have shown previously that not only does this fragment display a 1:1 stoichiom...

show abstract

Section: Immunoglobulin E (Ige)mentioning

confidence: 56%

Disulfide Linkage Controls the Affinity and Stoichiometry of IgE Fcϵ3–4 Binding to FcϵRI

Hunt

Beavil

Calvert

et al. 2005

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…2, both degalactosylated 6A6 IgG subclasses bound Ϸ2-fold better to MBL, whereas binding to C1q was decreased, consistent with earlier observations (15,25). Previous studies dealing with the effect of the lack of galactose on FcR binding were inconclusive, with some studies finding reduced binding (25)(26)(27), whereas others found only slight or no major changes (28)(29)(30)(31). Importantly, many of these studies used different methods, FcRs, and antibody isotypes, which might explain some of these contradictory results.…”

Section: Binding Of Igg-g0 Glycovariants To Fcrs and Complement Protementioning

confidence: 66%

Agalactosylated IgG antibodies depend on cellular Fc receptors forin vivoactivity

Nimmerjahn

Anthony²,

Ravetch³

2007

Proc. Natl. Acad. Sci. U.S.A.

228

178

View full text Add to dashboard Cite

IgG antibodies are glycoproteins containing a branched sugar moiety attached to the asparagine 297 residue in the antibody constant region (Fc). This glycan is essential for maintaining a functional Fc structure, which is a prerequisite for antibodymediated effector functions, such as the interaction with cellular Fc receptors or the complement component C1q. Variations in the composition of the sugar moiety can dramatically influence antibody activity. Moreover, humans and mice with autoimmune disorders, such as rheumatoid arthritis, have altered IgG glycosylation patterns with increased levels of antibodies lacking terminal sialic acid and galactose residues (IgG-G0). There is great interest in understanding whether this altered glycosylation pattern influences antibody-mediated effector functions. In vitro studies have suggested that IgG-G0 antibodies gain the capacity to activate the complement pathway via mannose-binding lectin (MBL), which could contribute to antibody-mediated inflammation. We have analyzed the activity of IgG-G0 antibodies in mice with a genetic deletion of MBL (MBL-null mice) and demonstrate that IgG-G0 antibodies are unimpaired in MBL-null mice. In contrast, the activity of these antibody glycovariants is fully dependent on the presence of activating Fc receptors.galactose ͉ glycosylation ͉ sialic acid ͉ inflammation

show abstract

“…2 Fc glycans are essential structural components of the IgG molecule and minor changes in glycan composition can significantly alter the conformation of the Fc region changing the interaction with receptor proteins and thus modulating the effector functions of IgG. 3,4 The lack of core fucose enhances the IgG1 binding to activating Fc receptor FcγRIIIa leading to increased antibody-dependent cellular cytotoxicity (ADCC) and destruction of target cells. 2,5−7 Moreover, the presence of sialic acid on the Fc N-glycans confers anti-inflammatory properties to IgG.…”

Section: ■ Introductionmentioning

confidence: 99%

High-Throughput IgG Fc N-Glycosylation Profiling by Mass Spectrometry of Glycopeptides

et al. 2013

View full text Add to dashboard Cite

Age and sex dependence of subclass specific immunoglobulin G (IgG) Fc N-glycosylation was evaluated for 1709 individuals from two isolated human populations. IgGs were obtained from plasma by affinity purification using 96-well protein G monolithic plates and digested with trypsin. Fc Nglycopeptides were purified and analyzed by negative-mode MALDI-TOF-MS with 4-chloro-α-cyanocinnamic acid (Cl-CCA) matrix. Age-associated glycosylation changes were more pronounced in younger individuals (<57 years) than in older individuals (>57 years) and in females than in males. Galactosylation and sialylation decreased with increasing age and showed significant sex dependence. Interestingly, the most prominent drop in the levels of galactosylated and sialylated glycoforms in females was observed around the age of 45 to 60 years when females usually enter menopause. The incidence of bisecting N-acetylglucosamine increased in younger individuals and reached a plateau at older age. Furthermore, we compared the results to the total IgG N-glycosylation of the same populations recently analyzed by hydrophilic interaction liquid chromatography (HILIC). Significant differences were observed in the levels of galactosylation, bisecting N-acetylglucosamine and particularly sialylation, which were shown to be higher in HILIC analysis. Age and sex association of glycosylation features was, to a large extent, comparable between MALDI-TOF-MS and HILIC IgG glycosylation profiling.

show abstract

Role of Oligosaccharide Residues of IgG1-Fc in FcγRIIb Binding

Cited by 226 publications

References 50 publications

Disulfide Linkage Controls the Affinity and Stoichiometry of IgE Fcϵ3–4 Binding to FcϵRI

Disulfide Linkage Controls the Affinity and Stoichiometry of IgE Fcϵ3–4 Binding to FcϵRI

Agalactosylated IgG antibodies depend on cellular Fc receptors forin vivoactivity

High-Throughput IgG Fc N-Glycosylation Profiling by Mass Spectrometry of Glycopeptides

Contact Info

Product

Resources

About