肉毒神经毒素B识别其蛋白质受体具有高亲和力和特异性
Rongsheng Jin1, Andreas Rummel, Thomas Binz
1Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.
Nature
|December 15, 2006
概括
肉毒神经毒素 (BoNTs) 通过synaptotagmin II和化物结合细胞. 对BoNT/B结合的这种结构性洞察力推动了针对这种神经毒素的疫苗和抑制剂的开发.
科学领域:
- 神经科学是一个神经科学.
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 肉毒神经毒素 (BoNTs) 是由肉毒 Clostridium botulinum 生产的高度有毒的蛋白质.
- 通过阻断神经肌肉结合处的神经递质释放,BoNTs会导致肉毒.
- 进入BoNT细胞和与受体结合的精确分子机制尚不清楚.
研究的目的:
- 阐明由其蛋白质受体识别肉毒神经毒素血清型B (BoNT/B) 的分子细节.
- 为了确定BoNT/B与其受体的复合体中的高分辨率结构,synaptotagmin II.
- 了解synaptotagmin II和团结体在BoNT/B结合和转移中的协同作用.
主要方法:
- 使用X射线晶体学以2.15 Å分辨率确定BoNT/B与synaptotagmin II的光域结合的结构.
- 生物化学测定和ex vivo神经元研究使用基于结构的突变进行.
- 分析不同类型和pH条件下不同类型的synaptotagmin结合性和选择性的结合性.
主要成果:
- 该结构揭示了synaptotagmin II如何在结合BoNT/B上的裂时诱导螺旋,该裂与类胺结合部位相邻.
- 在中性和酸性pH下,Synaptotagmin II与BoNT/B结合,具有纳米分子亲和力.
- 基于结构的突变证实了对synaptotagmin II的高特异性和亲和力,比synaptotagmin I具有选择性.
- 协同结合的synaptotagminII和化物限制了BoNT/B转位后的内细胞化.
结论:
- 确定的结构为通过synaptotagmin II.的BoNT/B识别提供了分子基础.
- 了解双受体相互作用对于BoNT/B细胞进入至关重要.
- 这些发现为合理设计新疗法铺平了道路,包括针对BoNTs的疫苗和抑制剂.
相关概念视频
G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
Receptor-mediated Endocytosis
Receptor-mediated endocytosis is when bulk amounts of specific molecules are imported into a cell after binding to cell surface receptors. The molecules bound to these receptors are taken into the cell through inward folding of the cell surface membrane, which is eventually pinched off into a vesicle within the cell. Structural proteins, such as clathrin, coat the budding vesicle.
Clathrin-Mediated Endocytosis of LDL
One well-characterized example of receptor-mediated endocytosis is the...
Clathrin-Mediated Endocytosis of LDL
One well-characterized example of receptor-mediated endocytosis is the...
G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
Directly Acting Muscle Relaxants: Dantrolene and Botulinum Toxin
Directly acting muscle relaxants like dantrolene and botulinum toxin (BoNT) have distinct mechanisms and applications. Dantrolene, a hydantoin derivative, acts on the ryanodine receptor (RYR1) in skeletal muscle cells. RYR1 are calcium channels present at the sarcoplasmic reticulum membrane. In response to excitation, they release calcium ions from the sarcoplasmic reticulum to the cytosol. Calcium promotes actin-myosin-mediated contraction of muscles.
The binding of dantrolene to the RYR1...
The binding of dantrolene to the RYR1...
Bacterial Toxins
Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
Botulism
Botulism is a life-threatening neuroparalytic condition caused by botulinum neurotoxin, which is produced by the bacterium Clostridium botulinum, a Gram-positive, spore-forming, obligate anaerobe.In adults, the toxin enters the body in different ways: in foodborne botulism, the preformed toxin is absorbed in the intestine. In wound botulism, spores grow in injured tissue and release the toxin into the blood. Infant botulism differs mechanistically from adult forms. In infants, botulism commonly...


