| 摘要: | 真菌屬於具有細胞壁但無葉綠體的多細胞真核微生物；其種類多樣且廣泛參與的碳素循環和固氮作用，在自然界中扮演聯繫無機物與生物之間的重要角色。此外，真菌的另一大特性為可分泌多種二次代謝物，這些二次代謝物具生物活性，其中大多擁有抗菌、抗毒性及抗腫瘤的功能，且近幾年來已被廣泛應用於食品工業、農業化學或醫藥材料的製作，屬於非常重要的自然資源。
由於這些真菌的二次代謝物具有多種功能，應用價值非常高，因此過去已有學者針對調控二次代謝物的真菌基因序列及其酵素作探討。例如：真菌Neosartorya fischeri的NRRL181基因序列與酵素─PKS和NRPS可調控其所分泌的二次代謝物，但是N. fischeri仍有許多二次代謝物尚待發掘；另一方面在腫瘤細胞研究顯示，利用histone deacetylase inhibitor及histone acetyltransferase inhibitor可以改變基因的表現情形。因此，本實驗以N. fischeri為對象，藉由不同的天數、藥物HDAC抑制劑SAHA和HAT抑制劑AA(anacardic acid)的參與，以及更改培養基配方的方式，並利用HPLC建立圖譜，觀察其二次代謝產物的變化，來看看是否能夠改變二次代謝物產量或是誘發不同的二次代謝產物。初步結果顯示，在處理HAT抑制劑時可以明顯增加N. fischeri的二次代謝物的吸光值，以AA較為明顯。
實驗室一般的培養條件之下的N. fischeri ，有許多表現微量的二次代謝物而不易被發掘，故本實驗所設定的環境及條件，即藉組蛋白乙醯化具DNA解纏繞的作用，相對活化DNA，誘導N. fischeri沈默基因群的二次代謝物的表現，期待能深入探討合成該二次代謝物相關的基因，且進行化合物結構分析，進而建立其表現條件模式比對系統，從中發現有效的天然化合物，作為可開發新藥物或研製醫療產品的新天然元素。
Classified as microorganism, fungi are multi-cellular eukaryotes without chloroplast. They are widely existed in soil, water, air and organism, and are involved in the carbon cycle and nitrogen fixation which are important in nature. In addition, most of the biological activities contained in fungi’s secondary metabolites come with the function of antibacterial, anti-toxic and anti-tumor. Thus it has been used in food industry, agricultural chemistry and medical materials.
The fungal gene sequences on regulating secondary metabolite and the enzyme have shown on previous studies. For example, the gene sequences NRRL181 of Neosartorya fischeri and the enzymes, PKS and NRPS, are able to regulate its secondary metabolites, though many of the secondary metabolites of N. fischeri are yet to be discovered; and some researches on tumor cells show that the performance of genes can be changed by sing histone deacetylase inhibitor and histone acetyltransferase inhibito. Using N. fischer as the subject, this experiment observe the amount and type change of its secondary metabolites by using time factor, HDAC inhibitors SAHA and HAT inhibitors AA(anacardic acid), the change of culture medium, and the map built by HPLC. According to the results, the absorbance of the secondary metabolites of N. fischeri increased when HAT was involved, especially with AA.
The unwrapping-DNA function of protein acetylating is used to activate DNA and to induce the performance of the secondary metabolites of N. fischeri silence gene cluster, which hoping to investigate the gene involved in synthesizing the secondary metabolites, and to build a system in order to discover the affective natural compounds as new element in drug developing and medical research. |
