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Title: | 探索致命病毒的潛力藥物:病毒3C及3CL蛋白酶與流感病毒之神經氨酸酶的抑制 Exploring the potent drugs for life-threatening viruses: Inhibition of 3C & 3C-Like Viral Proteases and Influenza Neuraminidase |
Authors: | Kian-Pin Tan 陳建儐 |
Advisor: | 梁博煌(Po-Huang Liang) |
Keyword: | 嚴重急性呼吸系統綜合症,3C 蛋白酶,3CL蛋白酶,流感病毒,神經胺酸酶,嘧啶化合物,吡,唑啉,酮化合物,3D-構效關係藥效團, Severe acute respiratory syndrome,3C protease,3CL protease,Influenza virus,Neuraminidase,Pyrimidine,Pyrazolone,3D-QSAR pharmacophore, |
Publication Year : | 2011 |
Degree: | 碩士 |
Abstract: | 嚴重急性呼吸系統綜合症是一種具高度傳染性和致命性的呼吸系統疾病。它是由一種在嚴重急性呼吸系統綜合症爆發之前都沒有被發現過的新型冠狀病毒所造成的,即SARS冠狀病毒。這種疾病於2003年爆發,且有近10%的疾病患者因此死亡。雖然至今已經七年沒有確診病例,但是有研究顯示蝙蝠是SARS冠狀病毒的自然寄主,所以對於此疾病的再度爆發仍有疑慮。在開發對抗這種病毒的藥物的過程當中,科學家發現SARS 3CL蛋白酶在病毒的複製過程當中扮演了非常重要的角色,也因此SARS 3CL蛋白酶的抑制也成為了一個非常重要的藥物開發方向。根據先前的研究指出,吡啶化合物可以作為 SARS 3CL蛋白酶可逆抑製劑,一系列的嘧啶化合物也基於此基礎上被合成。此外,我們實驗室之前也應用高通量藥物篩選發現了一些吡唑啉酮化合物可以同時有效的抑制3C和3CL蛋白酶。作為實驗的延續,一系列的吡唑啉酮化合物也因此被合成。實驗結果表明,其中一個嘧啶化合物能夠有效的抑制SARS 3CL蛋白酶,且半抑制率為6.1μM。此外,其中一個吡唑啉酮化合物可以同時分別以8.4μM,及9.6μM的半抑制率有效地抑制SARS 3CL蛋白酶及柯薩奇B3 3C蛋白酶。
流感病毒是一種單股負鏈的RNA病毒,同時它也是造成的季節性流感和流感大流行的罪魁禍首。血凝素和神經氨酸酶在流感病毒的生活史中扮演了非常重要的角色。其中,神經氨酸酶催化唾液酸的水解協助成熟流感病毒脫離宿主細胞感染新的細胞,因此抑制流感神經氨酸酶一個非常重要的藥物開發方向。 我們的實驗室在之前的高通量藥物篩選中發現,VK84可以以16.6μM的半抑制率,有效的抑制H5N1的神經氨酸酶。之後我們也根據電腦模擬的結果為VK84做了改進,合成了一系列的衍生物。 VK84是一種吡唑啉酮化合物,它的衍生物之一VK94經實驗證明能以1.7μM證明能的半抑制率,有效的抑制H1N1神經氨酸酶。根據對接結果,我們發現VK94是一個非常有吸引力的和潛力可以進行改良的抑製劑,並且通過改良從而更有效的抑制神經氨酸酶。 此外,為了提高高通量藥物篩選準確度,並且從中節省資金和精力,我們應用了Catalyst 4.10這套軟體建構了一個3D-QSAR藥效團。經過一系列的驗證,Hypo1似乎是一個具預測能力並且可用來進行虛擬高通量藥物篩選的可靠模型。總體而言,一個從虛擬高通量藥物篩選到抑制劑檢定的完整實驗流程已經被完整建立,並且肯定將在未來的藥物開發過程中扮演一定的角色。 Severe acute respiratory syndrome (SARS) is a highly contagious and fatal respiratory disease. It is caused by a novel coronavirus which never been discovered before the SARS, namely SARS-CoV. The outbreak of this deadly disease in 2003 had killed almost 10% of the infected patients. Although it has been 7 years since the last reported case of SARS, the evidences that bats are natural reservoirs of SARS-CoV have led to the concerns about the reemergence of the deadly disease. In search of the potential drugs against the deadly disease, SARS 3CLpro a protease which playing essential roles during the viral replication has been targeted for the drugs development. A series of pyrimidine compounds have been synthesized based on the findings that pyridine compounds could act as SARS 3CLpro reversible inhibitors. Furthermore, a series of pyrazolone compounds have also been synthesized as part of our laboratory’s continuation work of high throughput screenings. Some of the pyrazolone compounds have also been identified as common inhibitors for both 3C and 3CL protease, so that the Coxsackievirus B3 3Cpro have also been purified for further inhibition assay. The results show that one of the pyrimidine analogs could inhibit the SARS 3CLpro with an IC50 of 6.1μM. Meanwhile, a pyrazolone analog could inhibits SARS 3CLpro as well as inhibits CVB3 3Cpro with an IC50 of 8.4μM and 9.6μM respectively. Influenza viruses are negative sense, single-stranded, segmented RNA viruses. It is the viruses which cause the seasonal flu and even flu pandemics. Two glycoproteins, hemagglutinin and neuraminidase play very crucial roles during the influenza virus infection and replication. Neuraminidase facilitates the release of the replicate viruses from the infected cells by enzymatically cleavage of the sialic acid groups from host glycoproteins and hence it is a very good target for drugs development. VK84, an original hit that inhibits the H5N1 neuraminidase with an IC50 of 16.6 μM has been modified based on the computer modeling and a series of analogs were then been synthesized. VK84 is also a pyrazolone compound and one of its analogs, VK94, inhibits the H1N1 neuraminidase with an IC50 of 1.7μM. According to the docking results, VK94 shows some unexpected H-bonds and this made VK94 as an attractive and potential inhibitor for further modifications as pyrazolone compounds that have never been reported as neuraminidase inhibitors. Furthermore, in order to increase the accuracies and to save money and efforts for high throughput screening, Catalyst 4.10 was utilized to generate a reliable and predictive 3D-QSAR. The generated pharmacophore, Hypo1 has been validated and it seems that it is a reliable and predictive pharmacophore for virtual high throughput screening. In general, a complete procedure from the virtual high throughput screenings then to the inhibition assays has been developed. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/9014 |
Fulltext Rights: | 同意授權(全球公開) |
Appears in Collections: | 生化科學研究所 |
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