深入研究人类α1,4-银酸转移酶受体的特异性:酶二元化的作用
Krzysztof Mikołajczyk1, Karol Wróblewski2, Sebastian Kmiecik2
1Laboratory of Glycobiology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla St. 12, 53-114, Wroclaw, Poland.
Biochemical and biophysical research communications
|August 7, 2024
概括
人类α1,4-Galactosyltransferase (A4galt) 与其他甘氨酸转移酶形成二元,影响其对甘氨酸脂和甘氨酸蛋白的特异性. 这种二分化是理解Shiga毒素受体相互作用的关键.
科学领域:
- 生物化学 生物化学
- 葡萄糖生物学 葡萄糖生物学
- 分子细胞生物学 分子细胞生物学
背景情况:
- 人类的α1,4-银酸转移酶 (A4galt) 合成了Gb3糖脂和P1糖,作为Shiga毒素受体.
- 在A4galt多样化的受体特异性背后的分子机制尚不清楚.
研究的目的:
- 阐明A4galt对葡萄糖脂 (GSL) 和葡萄糖蛋白 (GP) 的特异性.
- 探索A4galt与其他甘氨基转移酶 (GTs) 的相互作用,特别是β1,4-氨基转移酶1 (B4galt1) 和异酶5和6 (B4galt5/6).
主要方法:
- 在HEK293T和CHO-Lec2细胞中使用了一种新的NanoBiT试验来检测A4galt同质化和B4galt1和B4galt5的异质化.
- 用AlphaFold进行酶复合物的结构预测,以分析相互作用.
主要成果:
- A4galt与B4galt1和B4galt5.5一起形成同质体和异质体.
- 异构体显示N端标签偏好,而同构体局部化因细胞系而异.
- A4galt-B4galt5异构体表现出最高的结构预测可靠性,这表明它在酶特异性中起着重要作用.
结论:
- A4galt异构化在确定其对GLS和GP的特异性方面发挥着至关重要的作用.
- 这些发现有助于更好地了解A4galt功能和与Shiga毒素相关的疾病机制.
相关概念视频
Oligosaccharide Assembly
2.8K
Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
Multiple sugar molecules that may or may...
2.8K
Activation and Inactivation of G Proteins
6.9K
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high...
6.9K
Proteoglycans
3.9K
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,...
3.9K
Cooperative Allosteric Transitions
7.9K
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
7.9K


