Naturally occurring structural isomers in serum IgA1 O -glycosylation

Kazuo Takahashi, Archer D. Smith, Knud Poulsen, Mogens Kilian, Bruce A. Julian, Jiri Mestecky, Jan Novak, Matthew B. Renfrow

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

IgA is the most abundantly produced antibody and plays an important role in the mucosal immune system. Human IgA is represented by two isotypes, IgA1 and IgA2. The major structural difference between these two subclasses is the presence of nine potential sites of O-glycosylation in the hinge region between the first and second constant region domains of the heavy chain. Thr 225, Thr 228, Ser 230, Ser 232 and Thr 236 have been identified as the predominant sites of O-glycan attachment. The range and distribution of O-glycan chains at each site within the context of adjacent sites in this clustered region create a complex heterogeneity of surface epitopes that is incompletely defined. We previously described the analysis of IgA1 O-glycan heterogeneity by use of high resolution LC-MS and electron capture dissociation tandem MS to unambiguously localize all amino acid attachment sites in IgA1 (Ale) myeloma protein. Here, we report the identification and elucidation of IgA1 O-glycopeptide structural isomers that occur based on amino acid position of the attached glycans (positional isomers) and the structure of the O-glycan chains at individual sites (glycan isomers). These isomers are present in a model IgA1 (Mce1) myeloma protein and occur naturally in normal human serum IgA1. Variable O-glycan chains attached to Ser 230, Thr 233 or Thr 236 produce the predominant positional isomers, including O-glycans composed of a single GalNAc residue. These findings represent the first definitive identification of structural isomeric IgA1 O-glycoforms, define the single-site heterogeneity for all O-glycan sites in a single sample, and have implications for defining epitopes based on clustered O-glycan variability.

Original languageEnglish
Pages (from-to)692-702
Number of pages11
JournalJournal of Proteome Research
Volume11
Issue number2
DOIs
Publication statusPublished - 03-02-2012
Externally publishedYes

Fingerprint

Glycosylation
Isomers
Immunoglobulin A
Polysaccharides
Serum
Myeloma Proteins
Epitopes
Amino Acids
Glycopeptides
Immune system
Hinges
Immune System
Electrons

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Chemistry(all)

Cite this

Takahashi, K., Smith, A. D., Poulsen, K., Kilian, M., Julian, B. A., Mestecky, J., ... Renfrow, M. B. (2012). Naturally occurring structural isomers in serum IgA1 O -glycosylation. Journal of Proteome Research, 11(2), 692-702. https://doi.org/10.1021/pr200608q
Takahashi, Kazuo ; Smith, Archer D. ; Poulsen, Knud ; Kilian, Mogens ; Julian, Bruce A. ; Mestecky, Jiri ; Novak, Jan ; Renfrow, Matthew B. / Naturally occurring structural isomers in serum IgA1 O -glycosylation. In: Journal of Proteome Research. 2012 ; Vol. 11, No. 2. pp. 692-702.
@article{777364f1d70549ea9ab887faab5438df,
title = "Naturally occurring structural isomers in serum IgA1 O -glycosylation",
abstract = "IgA is the most abundantly produced antibody and plays an important role in the mucosal immune system. Human IgA is represented by two isotypes, IgA1 and IgA2. The major structural difference between these two subclasses is the presence of nine potential sites of O-glycosylation in the hinge region between the first and second constant region domains of the heavy chain. Thr 225, Thr 228, Ser 230, Ser 232 and Thr 236 have been identified as the predominant sites of O-glycan attachment. The range and distribution of O-glycan chains at each site within the context of adjacent sites in this clustered region create a complex heterogeneity of surface epitopes that is incompletely defined. We previously described the analysis of IgA1 O-glycan heterogeneity by use of high resolution LC-MS and electron capture dissociation tandem MS to unambiguously localize all amino acid attachment sites in IgA1 (Ale) myeloma protein. Here, we report the identification and elucidation of IgA1 O-glycopeptide structural isomers that occur based on amino acid position of the attached glycans (positional isomers) and the structure of the O-glycan chains at individual sites (glycan isomers). These isomers are present in a model IgA1 (Mce1) myeloma protein and occur naturally in normal human serum IgA1. Variable O-glycan chains attached to Ser 230, Thr 233 or Thr 236 produce the predominant positional isomers, including O-glycans composed of a single GalNAc residue. These findings represent the first definitive identification of structural isomeric IgA1 O-glycoforms, define the single-site heterogeneity for all O-glycan sites in a single sample, and have implications for defining epitopes based on clustered O-glycan variability.",
author = "Kazuo Takahashi and Smith, {Archer D.} and Knud Poulsen and Mogens Kilian and Julian, {Bruce A.} and Jiri Mestecky and Jan Novak and Renfrow, {Matthew B.}",
year = "2012",
month = "2",
day = "3",
doi = "10.1021/pr200608q",
language = "English",
volume = "11",
pages = "692--702",
journal = "Journal of Proteome Research",
issn = "1535-3893",
publisher = "American Chemical Society",
number = "2",

}

Takahashi, K, Smith, AD, Poulsen, K, Kilian, M, Julian, BA, Mestecky, J, Novak, J & Renfrow, MB 2012, 'Naturally occurring structural isomers in serum IgA1 O -glycosylation', Journal of Proteome Research, vol. 11, no. 2, pp. 692-702. https://doi.org/10.1021/pr200608q

Naturally occurring structural isomers in serum IgA1 O -glycosylation. / Takahashi, Kazuo; Smith, Archer D.; Poulsen, Knud; Kilian, Mogens; Julian, Bruce A.; Mestecky, Jiri; Novak, Jan; Renfrow, Matthew B.

In: Journal of Proteome Research, Vol. 11, No. 2, 03.02.2012, p. 692-702.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Naturally occurring structural isomers in serum IgA1 O -glycosylation

AU - Takahashi, Kazuo

AU - Smith, Archer D.

AU - Poulsen, Knud

AU - Kilian, Mogens

AU - Julian, Bruce A.

AU - Mestecky, Jiri

AU - Novak, Jan

AU - Renfrow, Matthew B.

PY - 2012/2/3

Y1 - 2012/2/3

N2 - IgA is the most abundantly produced antibody and plays an important role in the mucosal immune system. Human IgA is represented by two isotypes, IgA1 and IgA2. The major structural difference between these two subclasses is the presence of nine potential sites of O-glycosylation in the hinge region between the first and second constant region domains of the heavy chain. Thr 225, Thr 228, Ser 230, Ser 232 and Thr 236 have been identified as the predominant sites of O-glycan attachment. The range and distribution of O-glycan chains at each site within the context of adjacent sites in this clustered region create a complex heterogeneity of surface epitopes that is incompletely defined. We previously described the analysis of IgA1 O-glycan heterogeneity by use of high resolution LC-MS and electron capture dissociation tandem MS to unambiguously localize all amino acid attachment sites in IgA1 (Ale) myeloma protein. Here, we report the identification and elucidation of IgA1 O-glycopeptide structural isomers that occur based on amino acid position of the attached glycans (positional isomers) and the structure of the O-glycan chains at individual sites (glycan isomers). These isomers are present in a model IgA1 (Mce1) myeloma protein and occur naturally in normal human serum IgA1. Variable O-glycan chains attached to Ser 230, Thr 233 or Thr 236 produce the predominant positional isomers, including O-glycans composed of a single GalNAc residue. These findings represent the first definitive identification of structural isomeric IgA1 O-glycoforms, define the single-site heterogeneity for all O-glycan sites in a single sample, and have implications for defining epitopes based on clustered O-glycan variability.

AB - IgA is the most abundantly produced antibody and plays an important role in the mucosal immune system. Human IgA is represented by two isotypes, IgA1 and IgA2. The major structural difference between these two subclasses is the presence of nine potential sites of O-glycosylation in the hinge region between the first and second constant region domains of the heavy chain. Thr 225, Thr 228, Ser 230, Ser 232 and Thr 236 have been identified as the predominant sites of O-glycan attachment. The range and distribution of O-glycan chains at each site within the context of adjacent sites in this clustered region create a complex heterogeneity of surface epitopes that is incompletely defined. We previously described the analysis of IgA1 O-glycan heterogeneity by use of high resolution LC-MS and electron capture dissociation tandem MS to unambiguously localize all amino acid attachment sites in IgA1 (Ale) myeloma protein. Here, we report the identification and elucidation of IgA1 O-glycopeptide structural isomers that occur based on amino acid position of the attached glycans (positional isomers) and the structure of the O-glycan chains at individual sites (glycan isomers). These isomers are present in a model IgA1 (Mce1) myeloma protein and occur naturally in normal human serum IgA1. Variable O-glycan chains attached to Ser 230, Thr 233 or Thr 236 produce the predominant positional isomers, including O-glycans composed of a single GalNAc residue. These findings represent the first definitive identification of structural isomeric IgA1 O-glycoforms, define the single-site heterogeneity for all O-glycan sites in a single sample, and have implications for defining epitopes based on clustered O-glycan variability.

UR - http://www.scopus.com/inward/record.url?scp=84863031236&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84863031236&partnerID=8YFLogxK

U2 - 10.1021/pr200608q

DO - 10.1021/pr200608q

M3 - Article

C2 - 22067045

AN - SCOPUS:84863031236

VL - 11

SP - 692

EP - 702

JO - Journal of Proteome Research

JF - Journal of Proteome Research

SN - 1535-3893

IS - 2

ER -