1. Author Correction: Analysis of O-glycoforms of the IgA1 hinge region by sequential deglycosylation
- Author
-
Yasuto Yokoi, Jan Novak, Naotake Tsuboi, Hisateru Yamaguchi, Daijo Inaguma, Tomohiro Mizuno, Kazuki Nakajima, Kazuo Takahashi, Yukihiro Fukamachi, Yukako Ohyama, Midori Hasegawa, Matthew B. Renfrow, and Yukio Yuzawa
- Subjects
Glycosylation ,Multidisciplinary ,Chemistry ,Science ,Published Erratum ,Glycopeptides ,Glomerulonephritis, IGA ,Computational biology ,High-Throughput Screening Assays ,Immunoglobulin A ,Polysaccharides ,Tandem Mass Spectrometry ,Medicine ,Humans ,Protein Isoforms ,Hinge region ,Author Correction ,Glycomics - Abstract
A common renal disease, immunoglobulin A (IgA) nephropathy (IgAN), is associated with glomerular deposition of IgA1-containing immune complexes. IgA1 hinge region (HR) has up to six clustered O-glycans consisting of Ser/Thr-linked N-acetylgalactosamine with β1,3-linked galactose and variable sialylation. IgA1 glycoforms with some galactose-deficient (Gd) HR O-glycans play a key role in IgAN pathogenesis. The clustered and variable O-glycans make the IgA1 glycomic analysis challenging and better approaches are needed. Here, we report a comprehensive analytical workflow for IgA1 HR O-glycoform analysis. We combined an automated quantitative analysis of the HR O-glycopeptide profiles with sequential deglycosylation to remove all but Gd O-glycans from the HR. The workflow was tested using serum IgA1 from healthy subjects. Twelve variants of glycopeptides corresponding to the HR with three to six O-glycans were detected; nine glycopeptides carried up to three Gd O-glycans. Sites with Gd O-glycans were unambiguously identified by electron-transfer/higher-energy collision dissociation tandem mass spectrometry. Extracted ion chromatograms of isomeric glycoforms enabled quantitative assignment of Gd sites. The most frequent Gd site was T
- Published
- 2021
- Full Text
- View/download PDF