LIGAND BINDING TO PROTEIN TOXIN DOMAINS

梭菌神经毒素，肉毒杆菌和破伤风， 通过蛋白质识别进入神经细胞， 结合位点。 我们目前正在研究 破伤风毒素（靶向结构域）及其结合的神经节苷脂 在细胞表面。 一系列有前景的配体， C片段上靠近神经节苷脂结合位点的位点是 通过计算“对接”来识别。 我们用的是电喷雾 光谱法来筛选配体， 与毒素的这个区域结合 一旦我们确定了各种 质谱法测定蛋白质/配体相互作用，更详细 可以设计实验来确定结合常数，并绘制结合常数图。 相互作用区域中的相邻氨基酸。 最终目标 本研究的一个重要方面是合成一种三齿配体， 竞争和阻碍神经节苷脂结合位点，作为一个 可能是毒素的抑制剂 未来的实验将研究 毒素/神经节苷脂复合物的结构和表征其孔 成形性能 本研究的基础研究方面将 了解非共价相互作用在 分子识别，这是正常细胞功能的关键过程， 一个经常被细菌和病毒利用的地方， 进入细胞。

The Clostridial neurotoxins, botulinum and tetanus, gain entry into neural cells by protein recognition involving cell specific binding sites. We are currently studying the C fragment of the tetanus toxin (the targeting domain) and the ganglioside it binds to on the cell surface. A series of prospective ligands that bind to two sites on the C fragment near the ganglioside binding site were identified by computational "docking". We are using electrospray mass spectrometry to screen the ligands and identify those that actually bind to this domain of the toxin. Once we have identified various protein/ligand interactions by mass spectrometry, more detailed experiments can be designed to determine binding constants and map the neighboring amino acids in the interacting regions. The ultimate goal of this research is the synthesis of a tridentate ligand which could compete with and obstruct the ganglioside binding site, acting as a possible inhibitor of the toxin. Future experiments would examine the structure of the toxin/ganglioside complex and characterize its pore forming properties. The basic research aspect of this study will provide an understanding of the role non covalent interactions play in molecular recognition, a process critical for normal cell function and one frequently exploited by bacteria and viruses to facilitate their entrance into cells.