蝎毒素多肽BmK AGAP的镇痛活性中心鉴定及与钠通道相互作用研究

Looking for an alternative to morphine is an important scientific problem needed to be solved in clinic. Buthus martensii and other insect drugs have beenwidely used to block analgesic in China since 3000 years ago. Evidence shows that the polypeptide is the mainly active substance. A variety of natural or artificial transformation of insect drugs have been approved by FDA. BmK AGAP (BmK analgesic an-titumoral peptide), an isolated peptide from the scorpion toxin, shows strong inhibitory effect on both somatic and visceral pain and also. It has also be reported that BmK AGAP doesn't show dependence and tolerance as opioid does, which provides new hope for designing new drug substituting for morphine. However, lacking of knowledge about the stucture and function relationship has hindered the new peptide drug design.With a multidisciplinary research approach, including polypeptide conformation analysis, total energy calculations, effective fragments exploration, point mutations and peptide synthesis, here we intend to explore the activity center of BmK AGAP and attempt to find out the structure-function relationship of BmK AGAP at atomic level by using electrophysiological and behavioral approaches, which would help us know more about the specific target. This project will open a wide perspective in designing various painkillers. Supplemented by computational biology experimental science, this research mode will promote to understand the structure and function of toxin peptide.

寻找替代吗啡类的高效、无耐受成瘾的镇痛药是临床亟待解决的科学难题。东亚钳蝎等虫药在镇痛领域的应用具有特色与优势，毒素多肽是其主要活性物质，目前已有多种虫药来源的天然或人工改造的多肽药成功上市。BmK AGAP是从东亚钳蝎毒腺中分离的α型长链多肽，课题组前期工作证实对躯体痛、内脏痛表现出较好的效果，且无吗啡的耐受依赖，但其构效关系及作用靶标不明确，这一缺陷阻碍了以其为模板的多肽药物设计。申请人拟通过原代神经元培养、表达细胞系验证对不同钠离子通道亚型电流的影响，了解镇痛机制；结合计算机同源模建、分子对接、虚拟突变与多肽化学合成等方法综合研究BmK AGAP的活性中心, 以期在原子水平阐明此类多肽结构和功能的关系；并通过神经电生理和行为学实验深入研究其与靶标相互作用，本项目将为寻找新型镇痛药提供先导结构。辅以计算生物学指导实验科学,且相互论证支持的研究模式有助于对虫药活性多肽结构与功能的理解。

寻找替代吗啡类的高效、无耐受成瘾的镇痛药是临床亟待解决的科学难题。东亚钳蝎等虫药在镇痛领域的应用具有特色与优势，毒素多肽是其主要活性物质，目前已有多种虫药来源的天然或人工改造的多肽药成功上市。BmK AGAP是从东亚钳蝎毒腺中分离的α型长链多肽，课题组前期工作证实对躯体痛、内脏痛表现出较好的效果，且无吗啡的耐受依赖，但其构效关系及作用靶标不明确，这一缺陷阻碍了以其为模板的多肽药物设计。申请人本项目经费的支持下开发出了BmK AGAP的高效活性制备工艺。并结合计算机同源模建、分子对接、虚拟突变与多肽化学合成等方法发现BmK AGAP的活性中心及与靶受体相互作用的关键氨基酸,阐明了以BmK AGAP的结构与功能的关系及其与钠通道的相互作用结构的结构基础。；进一步根据BmK AGAP与钠通道相互作用模式设计出了具有潜在镇痛活性的先导多肽。本研究将为基于蝎毒多肽寻找新型镇痛药提供先导结构，并进一步阐明蝎毒多肽镇痛的分子机制。并且本研究中涉及的计算生物学指导实验科学,且相互论证支持的研究模式有助于对虫药活性多肽结构与功能的理解。