Structural basis for recognition of synaptic vesicle protein 2C by botulinum neurotoxin A
Structural basis for recognition of synaptic vesicle protein 2C by botulinum neurotoxin A
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DOI：
10.1038/nature12732
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发表时间：
2014-01-02
期刊：
影响因子：
64.8
通讯作者：
Kammerer, Richard A.
中科院分区：
文献类型：
--
作者：
Benoit, Roger M.;Frey, Daniel;Kammerer, Richard A.
肉毒杆菌神经毒素A （BoNT/A）属于最危险的一类生物武器(1)。尽管如此，BoNT/A仍被广泛用于治疗常见疾病，如偏头痛和各种眼动和运动障碍(2)。BoNT/A最为人所知的用途可能是在化妆品中用作抗皱剂（包括肉毒杆菌和抗运动）。BoNT/A通过切割突触前神经末梢内的突触体相关蛋白25 (SNAP-25)，抑制神经递质乙酰胆碱的释放，从而导致肌肉长期弛缓性麻痹(4)。已经确定了两种类型的BoNT/A受体，这两种受体都是BoNT/A毒性所必需的，因此可能相互合作(5)：神经节苷脂和突触囊泡糖蛋白2 （SV2）家族的成员，它们是假定的转运蛋白，预计具有12个跨膜结构域，与毒素的受体结合结构域相关(5)。最近，成纤维细胞生长因子受体3 （FGFR3）也被报道为一种潜在的BoNT/ a受体(6)。在SV2蛋白中，BoNT/A结合位点已被定位到管腔结构域(7)，但BoNT/A与SV2相互作用的分子细节尚不清楚。在这里，我们确定了BoNT/A受体结合域（BoNT/A- rbd）与SV2C发光域（SV2C- ld）复合物的高分辨率晶体结构。SV2C-LD由一个右旋的四边形β -螺旋组成，它与BoNT/ a- rbd主要通过开放β -链边缘的主干-主干相互作用结合，其方式类似于淀粉样蛋白结构中的链间相互作用。竞争实验确定了一种抑制复合物形成的肽。我们的研究结果为开发新型抗毒素药物和合理设计具有更好治疗性能的BoNT/ a变体提供了强大的平台。
Botulinum neurotoxin A (BoNT/A) belongs to the most dangerous class of bioweapons(1). Despite this, BoNT/A is used to treat a wide range of common medical conditions such as migraines and a variety of ocular motility and movement disorders(2). BoNT/A is probably best known for its use as an antiwrinkle agent in cosmetic applications (including Botox and Dysport)(3). BoNT/A application causes long-lasting flaccid paralysis of muscles through inhibiting the release of the neurotransmitter acetylcholine by cleaving synaptosomal-associated protein 25 (SNAP-25) within presynaptic nerve terminals(4). Two types of BoNT/A receptor have been identified, both of which are required for BoNT/A toxicity and are therefore likely to cooperate with each other(5): gangliosides and members of the synaptic vesicle glycoprotein 2 (SV2) family, which are putative transporter proteins that are predicted to have 12 transmembrane domains, associate with the receptor-binding domain of the toxin(5). Recently, fibroblast growth factor receptor 3 (FGFR3) has also been reported to be a potential BoNT/A receptor(6). In SV2 proteins, the BoNT/A-binding site has been mapped to the luminal domain(7), but the molecular details of the interaction between BoNT/A and SV2 are unknown. Here we determined the high-resolution crystal structure of the BoNT/A receptor-binding domain (BoNT/A-RBD) in complex with the SV2C luminal domain (SV2C-LD). SV2C-LD consists of a right-handed, quadrilateral beta-helix that associates with BoNT/A-RBD mainly through backbone-to-backbone interactions at open beta-strand edges, in a manner that resembles the inter-strand interactions in amyloid structures. Competition experiments identified a peptide that inhibits the formation of the complex. Our findings provide a strong platform for the development of novel antitoxin agents and for the rational design of BoNT/A variants with improved therapeutic properties.