3 數據分析
代謝組學(xué)得到的是大量的、多維的信息,為了充分抽提數據中的潛在信息,對數據的分析需要應用一系列的化學(xué)計量學(xué)方法。在代謝組學(xué)的研究中,數據分析過(guò)程中應用的技術(shù)集中在模式識別技術(shù)上,模式識別技術(shù)主要有主成分分析(principalcomponents analysis,PCA)、非線(xiàn)形映射(nonlinearmapp ing,NLM)、簇類(lèi)分析(hierarchical cluster analysis,HCA)等非監督(unsupervised)研究方法和SMICA(soft independentmodeling of class analogy)、PLS-DA(PLS-discrmi inant analysis),ANN(artificial neural newtork)等監督(supervised)研究方法。PCA將分散于一組變量上的信息集中于幾個(gè)綜合指標上,如糖代謝、脂質(zhì)代謝、氨基酸代謝等,利用主成分(PC)描述機體代謝的變化情況,能夠簡(jiǎn)化數據并易化分析[19]。
4 代謝組學(xué)技術(shù)在微生物領(lǐng)域的應用
4.1 對微生物進(jìn)行分類(lèi)及篩選突變體
隨著(zhù)分子生物學(xué)的迅速發(fā)展,聯(lián)合基因型與表型對微生物進(jìn)行分類(lèi)已成為一種趨勢。代謝組學(xué)技術(shù)的發(fā)展使代謝譜分析方法(metabolic profiling)逐漸成為一種快速、高通量、全面的表型分類(lèi)方法,通過(guò)對代謝組的分析對細菌進(jìn)行分類(lèi)。Bu ndy等[20]通過(guò)代謝譜分析成功地區分開(kāi)臨床病理來(lái)源以及實(shí)驗室來(lái)源的不同桿菌(bacillus cereus)。在未發(fā)生明顯表型變化的突變體內,突變基因有可能導致某些代謝途徑發(fā)生變化,通過(guò)代謝組分析可以發(fā)現該突變體并研究相應基因的功能[21]。
4.2 在代謝工程領(lǐng)域的應用
U.Nasution[22]利用代謝組學(xué)手段通過(guò)動(dòng)態(tài)檢測恒化培養的Penicillium chrysogenum的糖酵解、三羧酸循環(huán)過(guò)程,認為通過(guò)修飾其新陳代謝能得到高產(chǎn)量的藥物,這些高產(chǎn)量的藥物與細胞內初級代謝有關(guān)。Dalluge等[23]利用LC-MS-MS方法監控發(fā)酵過(guò)程中的氨基酸譜紋,實(shí)現對整個(gè)發(fā)酵系統的牙體牙髓牙周病學(xué)雜志(Chin J Conserv Dent)2010,20(1)53高通量快速監控。Bernd Kammerera等[24]用反相高效液相色譜、電噴射質(zhì)譜、三聯(lián)四極質(zhì)譜在Strep tomyces species中尋找未知的媒介物、次級代謝產(chǎn)物,同時(shí)用MS-MS檢測極低濃度的氨基香豆素抗生素,檢測到一種新的化合物香豆霉素A1和10種不同的媒介物(有3種是新發(fā)現的),從而探索Streptomyces spespecies生物合成和發(fā)現新的潛在的抗生素。
5 代謝組學(xué)在口腔領(lǐng)域中的應用
隨著(zhù)代謝組學(xué)技術(shù)的發(fā)展,該方法也逐漸應用于口腔領(lǐng)域。李淼等[25]用代謝組學(xué)技術(shù)鑒定區分了兩種口腔常見(jiàn)致齲菌變形鏈球菌和黏性放線(xiàn)菌,認為代謝組學(xué)技術(shù)有望應用于口腔細菌的快速鑒定。Yan等[26]用代謝組學(xué)的方法對口腔鱗狀細胞癌、口腔扁平苔蘚和口腔白斑進(jìn)行了診斷,提示其作為一種有效的方法有望用于對口腔癌變及癌前病變進(jìn)行篩選。
代謝組學(xué)作為功能基因組學(xué)的重要組成部分,直接反應了生物體的生理狀態(tài),雖然其尚處于研究應用的初級階段,但通過(guò)代謝組學(xué)的研究極有可能去發(fā)現新的生化途徑并解釋正常的或病理的功能,如在口腔領(lǐng)域通過(guò)研究口腔致齲菌及其突變株的糖酵解途徑去分析不同的致病機理。代謝組學(xué)的成功發(fā)展不僅需要能快速檢測、鑒別和定量復雜代謝產(chǎn)物的技術(shù),還需要微生物學(xué)家、分析化學(xué)家、統計學(xué)家、信息學(xué)家的共同合作。相信隨著(zhù)代謝組學(xué)的發(fā)展一定能快速推進(jìn)生物醫學(xué)領(lǐng)域的飛速發(fā)展。
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