Glycosylated SV2 and gangliosides as dual receptors for botulinum neurotoxin serotype F.
Glycosylated SV2 and gangliosides as dual receptors for botulinum neurotoxin serotype F.
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DOI：
10.1021/bi9002138
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发表时间：
2009-06-23
期刊：
影响因子：
2.9
通讯作者：
Baldwin, Michael R.
中科院分区：
文献类型：
--
作者：
Fu, Zhuji;Chen, Chen;Barbieri, Joseph T.;Kim, Jung-Ja P.;Baldwin, Michael R.
肉毒杆菌神经毒素通过抑制神经肌肉接头处的乙酰胆碱释放而导致迅速的迟缓性瘫痪。已提出的7种BoNT血清型(A-G)通过神经节苷脂-蛋白双重受体与运动神经元结合。到目前为止，BoNT/F宿主受体相互作用的结构-功能特性还没有得到解决。本文报道了BONT/A和BONT/F的受体结合域的晶体结构和BONT/F的双重受体的特征。HCR/A的多肽折叠与BONT/A全毒素的受体结合域基本相同，并且HCR/F的结构与HCR/A非常相似，除了两个与神经元结合有关的区域外。固相阵列分析鉴定了两个HCR/F结合多糖：神经节苷脂GD1a和含有N-乙酰乳糖胺核心的寡糖。利用亲和层析，HCR/F结合天然突触囊泡糖蛋白作为蛋白质复合体的一部分。用α-岩藻糖苷酶、内切-β-半乳糖苷酶和PNGase F使糖蛋白去糖基化可阻断Hcr/F与Hcr/F的相互作用，而Hcr/B与其同源受体突触素I的结合不受影响。这些数据表明，HCR/F通过SV2的硫酸角蛋白部分与突触小泡糖蛋白结合。研究了HCR/F与神经节苷脂的相互作用。Hcr/F与中性糖核末端半乳糖上含有α2，3-连接唾液酸的神经节苷脂特异结合(结合顺序：GT1b=GD1a≫GM3；不与GD1b和GM1a结合)。Hcr/F的神经节苷脂结合口袋内的突变减少了与神经节苷脂、突触小泡蛋白复合体和原代大鼠海马神经元的结合。因此，BONT/F神经元的识别涉及对神经节苷脂和蛋白质(糖基化的SV2)碳水化合物部分的识别，为BONT/F对神经元的高亲和力和特异性提供了结构基础。
Botulinum neurotoxin causes rapid flaccid paralysis through inhibition of acetylcholine release at the neuromuscular junction. The seven BoNT serotypes (A-G) have been proposed to bind motor neurons via ganglioside- protein dual receptors. To date, the structure-function properties of BoNT/F host receptor interactions have not been resolved. Here we report the crystal structures of the receptor binding domains (HCR) of BoNT/A and BoNT/F and the characterization of the dual receptors for BoNT/F. The overall polypeptide fold of HCR/A is essentially identical to the receptor binding domain of the BoNT/A holotoxin, and the structure of HCR/F is very similar to that of HCR/A, except for two regions implicated in neuronal binding. Solid phase array analysis identified two HCR/F binding glycans: ganglioside GD1a and oligosaccharides containing an N-acetyllactosamine core. Using affinity chromatography, HCR/F bound native synaptic vesicle glycoproteins as part of a protein complex. Deglycosylation of glycoproteins using α- fucosidase, endo-β-galactosidase and PNGase F disrupted the interaction with HCR/F, while the binding of HCR/B to its cognate receptor, synaptotagmin I, was unaffected. These data indicate that the HCR/F binds synaptic vesicle glycoproteins through the keratan sulfate moiety of SV2. The interaction of HCR/F with gangliosides was also investigated. HCR/F bound specifically to gangliosides that contain α2, 3-linked sialic acid on the terminal galactose of a neutral saccharide core (binding order: GT1b = GD1a ≫ GM3; no binding to GD1b and GM1a). Mutations within the putative ganglioside binding pocket of HCR/F decreased binding to gangliosides, synaptic vesicle protein complexes and primary rat hippocampal neurons. Thus, BoNT/F neuronal discrimination involves recognition of ganglioside and protein (glycosylated SV2) carbohydrate moieties, providing a structural basis for the high affinity and specificity of BoNT/F for neurons.
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影响因子：
56.9
作者：
Dong, M;Yeh, F;Chapman, ER
通讯作者：
Chapman, ER
影响因子：
2.9
作者：
Baldwin, Michael R.;Barbieri, Joseph T.
通讯作者：
Barbieri, Joseph T.
影响因子：
9.4
作者：
Barash, JR;Tang, TWH;Arnon, SS
通讯作者：
Arnon, SS
影响因子：
3.1
作者：
Baldwin, Michael R.;Tepp, William H.;Barbieri, Joseph T.
通讯作者：
Barbieri, Joseph T.
影响因子：
2.9
作者：
Chen, Chen;Baldwin, Michael R.;Barbieri, Joseph T.
通讯作者：
Barbieri, Joseph T.