發(fā)布時(shí)間：2018-04-28 23:21

  本文選題：結(jié)核 + 耐藥　； 參考：《蘭州大學(xué)》2014年碩士論文

【摘要】：結(jié)核病是嚴(yán)重危害人民健康并可致命的一種慢性傳染病,其發(fā)病原因主要為結(jié)核分枝桿菌的感染。到目前為止,對(duì)于感染結(jié)核分枝桿菌的患者主要的治療方法就是抗結(jié)核化學(xué)藥物的聯(lián)合用藥。然而,耐多藥結(jié)核分枝桿菌菌株的出現(xiàn)在很大程度上減弱了藥物治療的有效性,對(duì)結(jié)核患者的治療帶來(lái)嚴(yán)重的影響。理解藥物與靶標(biāo)的相互作用和耐藥發(fā)生的分子機(jī)制對(duì)于設(shè)計(jì)和發(fā)現(xiàn)新的有效的抗結(jié)核藥物具有重要的指導(dǎo)價(jià)值�；诖吮菊撐慕Y(jié)合分子動(dòng)力學(xué)模擬及結(jié)合自由能等方法探究了結(jié)核分枝桿菌對(duì)抗結(jié)核藥物利福平以及異煙肼的耐藥機(jī)制。 論文第一部分主要是結(jié)合分子動(dòng)力學(xué)模擬以及MM-GBSA結(jié)合自由能計(jì)算方法探究了結(jié)核分枝桿菌RNA聚合酶β-亞單位的突變His526Asp、His526Tyr、 His526Arg、Ser531Trp和Ser531Leu對(duì)利福平產(chǎn)生耐藥性的分子機(jī)制。通過(guò)比較計(jì)算所得結(jié)合自由能的結(jié)果,突變體對(duì)利福平的耐藥性排序?yàn)镠is526Arg Ser531Leu His526Tyr His526Asp。氨基酸殘基與利福平分子之間的非極性相互作用的減弱是引起靶標(biāo)與利福平結(jié)合能力變?nèi)醯闹饕蛩?其中降低最為明顯的為His526Arg和Ser531Leu突變體。另外,對(duì)于Ser531Leu和His526Arg突變體來(lái)說(shuō),兩者的氣相能中的靜電相互作用能也產(chǎn)生明顯的減少。通過(guò)對(duì)復(fù)合物結(jié)合口袋進(jìn)行氫鍵相互作用以及表面性質(zhì)分析,我們發(fā)現(xiàn)第526位組氨酸和531位亮氨酸殘基分別發(fā)生突變后,不僅影響結(jié)合口袋大小以及疏水性強(qiáng)弱,也引起配體分子發(fā)生位移,從而在一定程度上影響氫鍵以及疏水相互作用的形成。 論文第二部分主要研究當(dāng)結(jié)核分枝桿菌enoyc-Acp還原酶上發(fā)生Ser94Ala、 Ile194Thr以及Ser94Ala/Ile194Thr氨基酸殘基突變后,對(duì)異煙肼(INH)產(chǎn)生耐藥性的分子機(jī)理。當(dāng)異煙肼進(jìn)入菌體之后被氧化成與煙酰胺腺嘌呤二核苷酸(Nicotinamide Adenine Dinucleotide,NAD)結(jié)合的活性形式——INH-NAD。對(duì)所有結(jié)合有INH-NAD的野生型和突變型復(fù)合物體系,根據(jù)結(jié)合自由能的大小,可將INH-NAD結(jié)合enoyc-Acp還原酶的能力從強(qiáng)到弱排列順序?yàn)閃T Ile194Thr Ser94Ala Ser94Ala/Ile194Thr。探究其突變引起結(jié)合變?nèi)醯脑虬l(fā)現(xiàn)突變均能引起極性相互作用能中靜電相互作用能與非極性相互作用能的減小,其中非極性相互作用能的減小是引起突變型復(fù)合物體系結(jié)合自由能減小的最關(guān)鍵因素。另外,極性相互作用能的減小與氫鍵作用的減弱或消失有著密切的關(guān)系。從結(jié)構(gòu)對(duì)比的結(jié)果來(lái)看,若發(fā)生Ile194Thr、Ser94Ala以及Ser94Ala/Ile194Thr突變后,會(huì)引起enoyc-Acp還原酶上INH-NAD結(jié)合口袋發(fā)生變化,從而使原有可以存在的enoyc-Acp還原酶上結(jié)合口袋與INH-NAD之間的氫鍵以及范德華相互作用受到影響,親和力降低。 本工作從分子水平探討了抗結(jié)核藥物與靶標(biāo)的相互作用以及靶標(biāo)突變導(dǎo)致結(jié)核分枝桿菌耐藥性發(fā)生的分子機(jī)制,得到的結(jié)果將為發(fā)現(xiàn)和設(shè)計(jì)針對(duì)耐藥結(jié)核的抗結(jié)核藥物提供重要的理論指導(dǎo)。
[Abstract]:Tuberculosis is a chronic infectious disease that seriously endangers the people's health and can be fatal, the main cause of which is Mycobacterium tuberculosis infection. So far, the main treatment for Mycobacterium tuberculosis patients is the combination of anti tuberculosis chemical drugs. However, the emergence of multi drug resistant Mycobacterium tuberculosis strains is very important. The understanding of the interaction between drug and target and the molecular mechanism of drug resistance have important guiding value for the design and discovery of new and effective anti tuberculosis drugs. Based on this theory, it combines molecular dynamics simulation and freedom. The resistance mechanism of Mycobacterium tuberculosis to rifampicin and isoniazid can be explored by other methods.
The first part of the thesis is to explore the molecular mechanism of the mutation of His526Asp, His526Tyr, His526Arg, Ser531Trp and Ser531Leu to rifampin, combined with molecular dynamics simulation and MM-GBSA binding free energy calculation method. The results of the combination of free energy are calculated by comparing the results of the comparison of the resistance to rifampin, His526Tyr, His526Arg, Ser531Trp and Ser531Leu. The resistance of the mutant to Li Fuping was sorted by the reduction of the non polar interaction between the His526Arg Ser531Leu His526Tyr His526Asp. amino acid residues and the Li Fuping molecule, which was the main factor causing the weakening of the binding ability of the target and Li Fuping, among which the most obvious was the His526Arg and Ser531Leu mutants. In addition, for Ser531Leu With the His526Arg mutants, the electrostatic interaction in the gas phase can also be significantly reduced. By hydrogen bonding interaction and surface properties analysis of the composite binding pockets, we found that the 526th - and 531 - bit leucine residues mutated respectively, not only affecting the size and hydrophobicity of the binding pockets. Strong and weak also cause the displacement of ligand molecules, thus affecting the formation of hydrogen bonds and hydrophobic interactions to a certain extent.
The second part of the paper mainly studies the molecular mechanism of drug resistance to isoniazid (INH) when Ser94Ala, Ile194Thr, and Ser94Ala/Ile194Thr amino acid residues are mutated on enoyc-Acp reductase of Mycobacterium tuberculosis. When isoniazid enters the fungus, it is oxidized to nicotinamide adenine dinucleotide (Nicotinamide Adenine Dinucleo). Tide, NAD) combining the active form of INH-NAD. to all the wild and mutant complexes with INH-NAD, based on the size of the binding free energy, the ability of INH-NAD to bind enoyc-Acp reductase from strong to weak sequence to WT Ile194Thr Ser94Ala Ser94Ala/ Ile194Thr. explores the cause of the mutation caused by the mutation. The present mutation can cause the decrease of the energy between the electrostatic interaction energy and the non polar interaction energy in the polar interaction energy, and the decrease of the non polar interaction energy is the most important factor causing the decrease of the free energy of the mutant complex system. From the results of structural contrast, if Ile194Thr, Ser94Ala, and Ser94Ala/Ile194Thr mutations occur, the INH-NAD binding pocket on the enoyc-Acp reductase can be changed, thus making the existing enoyc-Acp reductase binding to the hydrogen bond between the pocket and INH-NAD and the influence of the Fan Dehua interaction on the original enoyc-Acp reductase, and the affinity. The force is reduced.
In this work, the molecular mechanism of the interaction of anti tuberculosis drugs and targets and the molecular mechanism of the drug resistance of Mycobacterium tuberculosis caused by the target mutation are discussed. The results will provide important theoretical guidance for the discovery and design of anti tuberculosis drugs for drug-resistant tuberculosis.

【學(xué)位授予單位】：蘭州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：R52

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 屠德華;;艾滋病與結(jié)核病[J];結(jié)核病健康教育;2006年01期

2 裘志平;氟喹諾酮類(lèi)藥物在結(jié)核病治療中的應(yīng)用[J];華北煤炭醫(yī)學(xué)院學(xué)報(bào);2000年06期

3 宛寶山;張秋芬;周愛(ài)萍;趙國(guó)屏;姚玉峰;;結(jié)核分枝桿菌基因組學(xué)與基因組進(jìn)化[J];生物化學(xué)與生物物理進(jìn)展;2012年07期

4 唐神結(jié);肖和平;;結(jié)核病流行趨勢(shì)及治療未來(lái)展望[J];中國(guó)實(shí)用內(nèi)科雜志;2012年08期

5 陳英杰;孟玲宇;;結(jié)核病及其防治[J];中國(guó)當(dāng)代醫(yī)藥;2010年13期

6 黃海榮,馬s，

本文編號(hào)：1817359