HLAクラスI結合ペプチドに対する拡張O-GlcNAc
Fabio Marino1,2, Marshall Bern3, Geert P M Mommen1,2,4
1Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Journal of the American Chemical Society
|August 18, 2015
まとめ
研究者らは,ヒト白血球抗原 (HLA) クラスIペプチドに予期せぬ糖化作用を発見した. HLAペプチドのこれらの拡張されたO-リンクされたN-アセチルグルコサミン (O-GlcNAc) 変異は,免疫監視の重要な標的である可能性があります.
科学分野:
- 免疫学
- グライコバイオロジー
- マススペクトロメトリー
背景:
- ヒト白血球抗原 (HLA) クラスIの分子は,免疫監視に不可欠なT細胞にペプチドを提示する.
- 糖類の添加であるグリコシライゼーションは,通常,エンドプラズマ網とゴルギ装置のタンパク質で起こります.
- O結合型グリコシライゼーションは翻訳後の一般的な変異であるが,HLA結合型ペプチドにおけるその役割は十分に理解されていない.
研究 の 目的:
- グライコシル化HLAクラスI結合ペプチドの予期せぬ質量スペクトロメトリック観測を調査する.
- これらのグリコシレーションの性質と起源を特徴づける.
- これらの改変ペプチドの潜在的免疫性を調査する.
主な方法:
- ペプチドとグリカン分析のための質量スペクトロメトリー.
- 構造的な意味を理解するために 分子モデリング
- グリコシルトランスフェラーゼの活性を確認するための in vitro 酵素測定.
- グライカンの構造の解明のためのオキシオニウムイオンパターン分析.
主要な成果:
- 典型的な末端の改変を超えて,HLAクラスIペプチドのO結合グリカン識別.
- これらのグリカンは,GalNAc開始ではなく,拡張されたO-N-アセチルグルコサミン (O-GlcNAc) 構造である.
- 膜タンパク質から派生したOとN結合グリコペプチドの天然のHLAクラスIプレゼンテーションの最初の報告.
- HLAクラスIペプチドの中心部にあるオリゴサッカライドが免疫原性であることが観察された.
結論:
- HLAクラスIペプチドは,グリコシレーションに適した細胞区間を通過するため,複雑なO-GlcNAcグリコシレーションを受けることができます.
- これらのグリコシル化HLAペプチドは,特に中央オリゴサカリドを持つものは,免疫監視のための潜在的な標的を表しています.
- この発見は,HLA分子における翻訳後の改変とその免疫への影響に関する理解を広げています.
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