本文選題：抗抑郁　切入點：TREK-1通道　出處：《中國科學院大學(中國科學院上海藥物研究所)》2017年博士論文　論文類型：學位論文

【摘要】：當前抑郁癥已嚴重的影響到了人們的生活。抑郁癥的治療方法包括藥物治療、心理治療以及物理治療等。70%的抑郁癥患者經(jīng)過抗抑郁藥物治療后都可緩解癥狀,因而高效安全的抗抑郁藥物已成為藥物研發(fā)的熱點。TREK-1通道屬于雙孔鉀離子通道(K2P)。TREK-1通道在人的海馬、皮質、杏仁核等腦區(qū)大量存在,與單胺神經(jīng)遞質系統(tǒng)高度相關�？挂钟魟游锬Ｐ秃突蚯贸芯勘砻饕种芓REK-1通道可以治療抑郁,TREK-1通道已成為新型抗抑郁藥物設計的重要靶標。但是目前我們對TREK-1通道的失活機制以及與小分子的結合方式仍缺乏了解。分子動力學(Molecular dynamics,MD)模擬是一種研究蛋白質動態(tài)行為和功能關系的有效方法,它可在原子水平上模擬蛋白質的動態(tài)行為,提供構象變化的細節(jié),為蛋白質的功能研究提供重要信息。本論文運用分子動力學模擬和分子對接方法研究了TREK-1通道的結構與功能,闡明了胞外p H調(diào)控TREK-1通道失活機制、小分子與TREK-1通道的胞外Cap區(qū)的結合方式以及TREK-1通道跨膜區(qū)域的動態(tài)行為。TREK-1通道是酸敏感性鉀離子通道。TREK-1通道胞外側loop上的殘基His126是感應胞外酸環(huán)境的主要位點。為了研究胞外p H調(diào)控TREK-1通道的分子機制,我們利用MD技術觀察了His126質子化和非質子化條件下,TREK-1通道在POPC膜中的動態(tài)行為差異。我們發(fā)現(xiàn)在這兩種條件下,TREK-1通道的“選擇性濾器”結構傾向于不同的構象。His126殘基的質子化通過穩(wěn)定“選擇性濾器”結構周圍的氫鍵網(wǎng)絡而使TREK-1通道處于不傳導狀態(tài)。K2P通道的結構上的一個明顯特征是胞外側形成一個有四個螺旋結構組成的Cap區(qū)。一直以來有關K2P通道的Cap區(qū)的功能不是太清楚。在本論文中,我們通過以我們發(fā)現(xiàn)的TREK-1通道的抑制劑小分子TKDC為探針,結合計算,突變以及電生理等相關技術表明TREK-1通道的Cap區(qū)是小分子結合的潛在位點。分子動力學模擬發(fā)現(xiàn)小分子TKDC可以誘導Cap區(qū)的構象變化使TREK-1通道胞外的離子通路阻塞。盡管很多研究表明TREK家族通道的門控位點在“選擇性濾器”結構上,但是TREK家族通道的跨膜區(qū)域對于調(diào)控通道的活性仍然很重要。目前的晶體結構揭示TREK家族通道的結構主要存在兩種構象,Down構象和Up構象。突變,化學交聯(lián)以及藥理實驗等相關研究表明Up構象有利于TREK家族通道維持激活狀態(tài)。我們利用MD模擬揭示了TREK-1通道由Down狀態(tài)轉變成Up狀態(tài)的過程”。通過對該轉變過程的分析,我們預測TREK-1通道的一個亞基M4螺旋與另一個亞基的M2螺旋之間(Site1),以及同一個亞基上M2、M3以及M4的胞內(nèi)側螺旋之間(Site2)存在抑制劑結合位點。Site1位點已被TREK-2通道的晶體結構所證實。我們通過對Site2位點進行虛擬篩選,發(fā)現(xiàn)該位點也可以結合小分子抑制劑。
[Abstract]:At present, depression has a serious impact on people's lives. The treatment of depression includes medication, psychotherapy and physical therapy, and .70% of depression patients can relieve their symptoms after treatment with antidepressant drugs. Therefore, high efficient and safe antidepressants have become a hot spot in drug research and development. TREK-1 channel belongs to the double pore potassium channel. K2PU. TREK-1 channel is abundant in the hippocampus, cortex, amygdala and other brain regions of human beings, such as hippocampus, cortex, amygdala and so on. Antidepressant animal model and gene knockout study indicate that inhibiting TREK-1 channel can treat depression and TREK-1 channel has become an important target for the design of new antidepressant drugs. The mechanism of channel inactivation and the way of binding to small molecules are still not well understood. Molecular dynamics molecular dynamics (MD) simulation is an effective method to study the dynamic behavior and functional relationship of proteins. It can simulate the dynamic behavior of protein at atomic level, provide the details of conformation change, and provide important information for the study of protein function. In this paper, molecular dynamics simulation and molecular docking method are used to study the structure and function of TREK-1 channel. The mechanism of TREK-1 channel inactivation regulated by extracellular pH was elucidated. The binding mode of small molecules to the extracellular Cap region of TREK-1 channel and the dynamic behavior of the transmembrane region of TREK-1 channel. TREK-1 channel is the main site of acid-sensitive potassium channel. TREK-1 channel on the extracellular loop is the main site of acid-sensitive potassium channel. In order to study the molecular mechanism of TREK-1 channel regulated by extracellular pH, The dynamic behavior of TREK-1 channel in His126 membrane was observed by MD technique. We found that the "selective filter" structure of TREK-1 channel tended to be different conformation under these two conditions. His126. The protonation of the residue makes the TREK-1 channel unconductive by stabilizing the hydrogen bond network around the "selective filter" structure. An obvious feature of the structure of the K2P channel is the formation of a four-helix structure on the outside of the cell. Cap region. The function of Cap region of K2P channel is not very clear all the time. We used a small molecule of TKDC, an inhibitor of the TREK-1 channel, that we discovered as a probe, combined with calculations. Mutation and electrophysiological techniques showed that the Cap region of TREK-1 channel was the potential site for small molecule binding. Molecular dynamics simulation showed that small molecule TKDC could induce conformation change of Cap region and block the extracellular ion pathway of TREK-1 channel. Although many studies have shown that the gated site of the TREK family channel is in the "selective filter" structure, However, the transmembrane region of the TREK family channel is still very important for regulating the channel activity. The current crystal structure of the TREK family channel reveals that there are two main conformational conformations: down conformation and up conformation. Chemical crosslinking and pharmacological experiments have shown that up conformation is beneficial to maintain the activated state of TREK family channels. We use MD simulation to reveal the process of TREK-1 channel transition from Down state to up state. We predict the existence of an inhibitor binding site, Site1, between one subunit M4 helix of the TREK-1 channel and the M2 helix of another subunit, and the Site1 site on the same subunit between M2M3 and M4 medial helix. The Site1 site has been formed by the crystal junction of the TREK-2 channel. We do virtual screening of Site2 loci, It was also found that this site could bind to small molecular inhibitors.
【學位授予單位】：中國科學院大學(中國科學院上海藥物研究所)
【學位級別】：博士
【學位授予年份】：2017
【分類號】：R91

【參考文獻】

相關期刊論文 前2條

1 王剛;胡昌清;豐雷;肖樂;;中國抑郁障礙的研究現(xiàn)狀與展望[J];中華精神科雜志;2015年03期

2 葉冬青;張志s，

本文編號：1583814