Merz Pharmaceuticals GmbH, Potsdam, Germany.
Eur J Neurol. 2009 Dec;16 Suppl 2:11-3. doi: 10.1111/j.1468-1331.2009.02879.x.
Botulinum toxin type A (BoNT/A) is a well-established treatment for conditions characterized by muscle and autonomic nerve terminal overactivity, such as cervical dystonia and blepharospasm, and hyperhidrosis, respectively. BoNT/A is not digested in the gastrointestinal tract as it forms a complex with several proteins that protect and stabilize the neurotoxin. However, the pure neurotoxin is solely responsible for the therapeutic effect, and the complexing proteins have been shown to exhibit immunostimulating activity. The complexing proteins are not required for the stabilization of the neurotoxin in a formulation; the complexing proteins immediately dissociate from the neurotoxin at a physiologic pH, so they do not influence the spread of the neurotoxin. Xeomin is the only botulinum toxin that is free from complexing proteins and is stable at room temperature for a period of 4 years. When injected directly into muscles, Xeomin inhibits local neuromuscular cholinergic transmission, causing focal weakness. It binds to motor nerve terminal pre-synaptic receptors, is internalized via receptor-mediated endocytosis and then selectively cleaves a protein called SNAP-25. This is one of several so-called 'SNARE' proteins involved in exocytosis. Cleavage of SNAP-25 inhibits the secretion of acetylcholine causing the paralysis of the muscle. The clinical effects begin 24-72 h after injection, peak at approximately 4-6 weeks and are sustained for several months.
A型肉毒毒素（BoNT/A）是一种成熟的治疗方法，适用于肌肉和自主神经末梢过度活跃的疾病，如颈肌张力障碍、眼睑痉挛和多汗症。BoNT/A 在胃肠道中不会被消化，因为它与几种保护和稳定神经毒素的蛋白质形成复合物。然而，纯神经毒素是唯一负责治疗效果的物质，而复合蛋白已被证明具有免疫刺激活性。对于制剂中神经毒素的稳定，复合蛋白不是必需的；在生理 pH 值下，复合蛋白会立即从神经毒素中解离，因此它们不会影响神经毒素的扩散。Xeomin 是唯一一种不含复合蛋白的肉毒毒素，在室温下稳定 4 年。当直接注射到肌肉中时，Xeomin 抑制局部神经肌肉胆碱能传递，导致局部肌无力。它与运动神经末梢突触前受体结合，通过受体介导的内吞作用内化，然后选择性地切割一种称为 SNAP-25 的蛋白质。这是参与胞吐作用的几种所谓“SNARE”蛋白之一。SNAP-25 的切割抑制乙酰胆碱的分泌，导致肌肉瘫痪。注射后 24-72 小时开始出现临床效果，约 4-6 周达到高峰，并持续数月。
