一种具有替代甘氨酸特异性的内葡萄糖酶允许扩大甘氨酸蛋白重塑
Jonathan J Goodfellow1, Kavitha Baruah, Keisuke Yamamoto
1Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK.
Journal of the American Chemical Society
|May 4, 2012
概括
一种新的细菌内葡萄糖酶,EndoS,为蛋白质甘氨酸重塑提供了增强的选择性. 这种酶处理复杂类型的N链 glycans,解决以前困难的抗体糖形.
科学领域:
- 生物化学 生物化学
- 葡萄糖生物学 葡萄糖生物学
- 酶学 是一种酶学.
背景情况:
- 蛋白质内葡萄糖酶对于生物催化对蛋白质结合的甘氨酸进行修改至关重要.
- 现有的内葡萄糖酶酶的选择性有限,阻碍了对各种N结合甘氨酸的操纵.
- 某些与N结合的甘氨酸结构仍然不适合当前的酶处理方法.
研究的目的:
- 为了识别和表征新的内葡萄糖酶,提高了对蛋白质甘氨酸重塑的选择性.
- 评估细菌内葡萄糖酶的互补活性,EndoS,与现有的酶如EndoA和EndoH一起.
- 为了使以前难以处理的N结合甘氨酸结构能够有效地操纵蛋白质,特别是抗体.
主要方法:
- 来自Streptococcus pyogenes的细菌内葡萄糖酶 (EndoS) 的分离和表征.
- 生物催化测试以确定EndoS.的基质特异性.
- 使用各种 N-链 glycan 基质对已知 endoglycosidases (EndoA, EndoH) 的 EndoS 活性进行比较分析.
- 应用EndoS用于处理复杂类型的N链 glycans,包括那些与核心 fucosylation.
主要成果:
- EndoS表现出明显的基质特异性,与EndoA和EndoH不同.
- EndoS有效地处理复杂类型的N链 glycans,有或没有核心 fucosylation.
- EndoS 不处理寡甘或混合型N链 glycans.
- 这种选择性活动扩大了酶性甘氨酸改造的工具包.
结论:
- 细菌内葡萄糖酶EndoS为蛋白质糖甘修饰提供了一个补充的酶活性.
- EndoS能够处理复杂类型的N链 glycans,包括那些在耐火抗体 glycoforms 中发现的.
- 这一发现推动了蛋白质工程和甘氨酸操纵领域的发展.
相关概念视频
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Multiple sugar molecules that may or may...
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Protein Glycosylation
Glycosylation, the most common post-translational modification for proteins, serves diverse functions. Adding sugars to proteins makes the proteins more resistant to proteolytic digestion. Glycosylated proteins can act as markers and receptors to promote cell-cell adhesion. Additionally, they have many essential quality control functions in the cell, such as correct protein folding and facilitating transport of misfolded proteins to the cytosol, which can be degraded.
Glycosylation occurs in...
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Glycans, a class of complex heterogeneous molecules, can be covalently attached to proteins to form glycosylated proteins that regulate various physiological and pathological processes. Glycosylated proteins or glycoproteins comprise N-linked and O-linked oligosaccharides. O-glycosylation is the most common type of protein glycosylation. Here, glycans attach to the oxygen atom of the hydroxyl groups of Serine or Threonine residues. O-linked glycosylation occurs later in protein processing,...
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Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
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