生物化學

高中生物課本內對於轉譯機制所舉的例子，通常僅侷限於轉譯起始階段(initiation)所受的調控，例如色胺酸調控組。因此，我們想藉此研究更進一步探討：細胞在不同階段是否有調控轉譯的現象。我們利用冷光蛋白測定法(luciferase reporter assay)測出CPEB3的確對於轉譯有減緩的效果，並利用不同internal ribosome entry site(IRES)間接證明轉譯速率的變化主要是根據延長階段的不同而有所改變。另一方面，我們將多組CPEB3突變株進行交叉分析，找出cpeb3序列中兩百多個鹼基對的重要基因片段，並發現其為不連續的基因，且用Co-Immunoprecipitation(Co-IP)驗證我們的實驗結果。未來，我們將繼續探討在延長階段抑制的意義，以助於我們進一步了解細胞轉譯的過程。

This research is mainly in observation with Caenorhabditis elegans ’s genetic mutation caused via nervous system abnormal character. In the study, I the sample have been cultivated purified and add some chemical material EMS to speed up C.elegans mutation. Then based on the character to further analysis what causeof gene deal with mutation and observe the effects in heredity. The research has two stages, on the first stage of study the mainly target is to both search and purify the mutation of C.elegans. The second stage is based on the exploration of mutation’s searching andpurifying. Because the certain mutation bodies aren’t easy to find out, the project is still on progress at the beginning of second stage, and we conclude some heredity special cases in preliminary of study. 這個實驗主要是觀察並針對線蟲因為基因的突變所產生的神經系統異常的變異性狀，在實驗中我先將樣品線蟲培養並純化至一定數量，並加入適當藥劑EMS造成其突變，經篩選並分析此性狀，進而找出造成其突變之基因，以及觀察此性狀對遺傳表現所造成的影響。 該計畫分成兩階段，第一階段的實驗重點是在突變株的搜尋以及純化上，第二階段則是在突變基因的探討上，由於特定突變株的搜尋並非容易，所以目前計畫只進展至第二階段的遺傳實驗初期，對於其遺傳特徵與突變形式上已有了初步的分析，但尚未定位出該基因的位置。

我們的研究報告，是對校園中所種植的各種變葉木所做的一個研究，經過一連串的實驗證明後，我們確信花青素對變葉木的光合作用會有所影響。接著，我們測定出未氧化的植物色素與已氧化的植物色素吸光能力有很大的差異，我們假設花青素可以吸收某些特定波長的光以防止植物色素的氧化程度過強，實驗後證明我們的假設是正確的。另一方面，我們預期花青素具有保溫的機制，故設計了一個在低溫下花青素可保溫的實驗以證明之，結果和我們的假設相符合。我們預期花青素可利用保溫的特性降低植物因低溫所造成的傷害，減少農業上的損失。This study is about the Codiaeum variegatum which is grown on campus. After a series of experiments, it was proved that “anthocyanin” has a significant influence on the photosynthesis processing in Codiaeum variegatum. A great difference in the pigment of plant’s light-absorbing ability between the oxidized plants and the non-oxidized ones was also found in the experiments. Therefore, it was supposed that anthocyanin could absorb some special range of wavelength to avoid the pigment of plant to over-oxidize. The result of this experiment is in accordance with our supposition. In addition, we anticipated that anthocyanin has the ability to stay warm. By a designed experiment we successfully found that the result is exactly the same as our assumption. According to the findings of our study, we expect the characteristic -- ”staying warm” of anthocyanin could be applicable to decrease the harm to plants caused by the low temperature, and thereby to reduce the loss in agriculture.

顆粒澱粉可和碘形成藍色錯合物(starch-iodine complex)，我從種子發芽澱粉酶實驗了解澱粉酶(amylase)具糖解酵素活性，會分解澱粉盤上的澱粉，並使澱粉失去與碘形成螺旋狀澱粉-碘錯合物的能力，讓藍色澱粉盤出現透明水解圈。通常澱粉酶之分子結構包含澱粉吸附區及催化區，分別負責吸附大分子或不可溶性澱粉糖(amylose)配體及分解澱粉糖成可溶性小分子糖。本計劃選用分子量、溶解度不同的澱粉糖分別與碘液反應，再加入澱粉酶(glucoamylase)或其澱粉吸附區(starch binding domain, SBD)，發現二者均會破壞澱粉糖與碘結合之螺旋狀結構。分析二者之反應效率，可比較不同蛋白質解開澱粉-碘錯合物之能力。此外，本研究亦比較正常與突變株二聚體澱粉吸附區(SBD dimer)之解開澱粉-碘錯合物反應活性，再查詢文獻、比對不同蛋白質的序列、結構、及功能特性進行綜合分析。根據本研究結果，澱粉吸附蛋白質序列中解開配體螺旋結構最重要的官能基為兩個具有苯環的胺基酸，且二者對於可溶性及不可溶性配體之影響不同。本研究提供科學家了解自然界具備重複澱粉吸附區(tandem repeat)功能的邏輯方法，未來可應用於澱粉代謝、合成相關之蛋白質設計、結構預測、及功能分析。.

The physiochemical properties of fullerenes have aroused wide interest, such as its ability to accept and lose electrons and relatively high reactivity that permit various modes of structural modifications. However, obstacles to further research include its complete lack of solubility in water and low processability.\r This project investigated the morphology and microstructure of a fullerene-grafted polymer as a potential candidate for better and novel systems for drug delivery. In this research, hydrophilic functionalities were introduced to the C60 fullerene by chemical modifications, through the attachment of poly(acrylic acid) (PAA) chain. The objective was to investigate the dynamics and the self-assembly properties of this polymer in aqueous solutions, and the knowledge gained would enhance the development of such system for potential applications in drug delivery and nanotechnology.

茶品的發酵程度對其香氣與口感有決定性的影響，然而業界卻缺乏相關的客觀指標與其有效的量測方法。茶品發酵的主要化學過程是其兒茶素的氧化與聚合，這些茶單寧將隨著發酵過程逐漸由還原態轉變成氧化態。所以，不同發酵程度的茶，其氧化態單寧與還原態單寧的比將有所不同。這個比值預料可由氧化還原電位間接地量測得知。本研究使用白金絲與銀/氯化銀參考電極為電極對來量測此氧化還原電位。量具則使用具高輸入阻抗(大於十億歐姆)的pH 電極用電位計以取得茶汁中微弱的氧化還原電位訊號，可於十秒內取得高再現性(相對標準差小於3%)的電位訊號所得到的電位訊號與發酵程度呈高度的線性相關(相關係數大於0.9)。Degree of fermentation is pivotal for the aroma and the aftertaste of tea, but an objective scale and efficient evaluating methods are demanded for the important quality factor. Oxidation along with the polymerization of catechins is known to be the major chemical process during tea fermentation; the tea tannins will gradually change from their reduced forms to their oxidized formats. As the consequence, the ratio of oxidized tannins to reduced tannins will differ with the extent of fermentation. The ratio can be measured simply by the redox potential. In the present study, we used a platinum wire and an Ag/AgCl reference electrode as the electrode pair to measure the redox potential. A pH meter with high input impedance (over Giga ohm) served as our voltmeter for the weak voltage signals retrieved from tea infusions. The measurement was quick (less than 10 second) and with good reproducibility (CV0.9).

Entamoeba histolytica is a protozoan parasite known to cause infectious colitis and amoebic dysentery in humans. Its life cycle consist of two parts: the infectious cyst stage and the multiplying trophozoite stage. Epinephrine, a neurotransmitter in vertebrates, is released by the trophozoites during the process of cyst formation. The addition of epinephrine to in vitro cultures of amoebas causes them to encyst, and addition of compounds that prevent epinephrine’s activity inhibits encystations. Therefore, epinephrine plays a critical role in encystation in vitro. An understanding of the molecular intricacies of epinephrine-induced encystations may allow for pharmacological manipulation of epinephrine metabolism to control cyst formation in vitro. Drugs that either prevent cyst formation or induce it before a large amoebic population is present would result in the release of fewer cyst forms of the parasite, reducing parasite transmission from person to person. Although trophozoites release epinephrine, it is no known if E.histolytica synthesizes epinephrine or extracts it from the growth medium. Phenylethanolamine N-methyltransferase(PNMT) is the enzyme that catalyzes production of epinephrine norepinephrine. This study aims to determine the source of epinephrine by determining if E.histolytica contains a PNMT-type enzyme. PNMT amino acid sequences from several higher organisms were compared to identify conserved regions of the enzyme. These conserved amino acid sequences were then used to search for similar sequences in a database containing the recently sequenced amoeba genome. A PNMT-like gene was found in the E.histolytica database and cloned in bacteria. Yeast cells containing the cloned E.histolytica PNMT gene expressed PMT enzyme activity. This suggests that E.histolytica produces its own epinephrine, and is the most evolutionarily ancient eukaryote shown to do so. The use of inhibitors against PNMT activity is under investigation.

CD157 is a 31kDa ectoenzyme that is expressed at elevated levels in patients\r with rheumatoid arthritis (RA). The full function of this protein has yet to be\r determined, and the correlation between CD157 and RA is not well\r understood.

K562細胞是一種人類慢性骨髓性白血病細胞株，普遍用於研究幹細胞分化的先驅細胞，可以藉不同誘導劑分化成紅血球或巨核細胞。此研究聚焦於兩種臨床藥物：抗病毒藥物Ribavirin和組蛋白去乙醯化抑制劑SAHA，探討其誘導K562細胞紅血球分化機制。其中針對一個在許多分化機制扮演重要角色的染色質修飾蛋白TIFβ來研究，它可以召集其他轉錄因子在基因上形成抑制複合體。我們藉由定點突變探討TIFβ上的bromo或RBCC domain的乙醯化狀態對於TIFβ與抑制複合體的轉錄因子交互作用的影響。研究結果發現乙醯化RBCC domain大幅影響了TIFβ與轉錄因子的親和力，並且降低TIFβ三聚體的形成，可能導致抑制複合體無法形成進一步開啟了分化的通道。

The role of Notch signaling in the regulation of growth and differentiation of epithelial stem cells is poorly understood. While specific markers for epidermal stem cells have not yet been identified, members the Notch signaling pathway have been reported to be differentially expressed in the human epidermis. This study sought to demonstrate the presence and distribution of Notch and its ligands, Delta and Jagged, in human keratinocytes, and thereby characterize this subpopulation. Human neonatal foreskin samples were used to obtain isolated epidermal cells. Cells that were shown to be negative for connexin43, a gap junction protein, and positive for keratin14, a basal marker, were classified as presumptive stem cells (PSC). This sorted subpopulation was shown to be small and agranular by flow cytometry analysis. After two weeks in cell culture, PSC revealed a proliferative potential three times greater than non-sorted cells. The PSC exhibited increased expression of Delta and Jagged ligands than the general population. Additionally, RT-PCR confirmed the presence of Jagged and Delta in keratinocytes; however, only Jagged was detected in immunohistochemistry tests. Members of the Notch family were identified by immunohistochemistry in the epithelium and also at the protein- and mRNA-level. The data suggests that variations in the expression of members of the Notch signaling pathway could potentially be used as markers for stem cells of the epithelium; however, further research is necessary to make definitive conclusions, which would provide better insight into Notch regulatory pathways. This understanding could one day allow for the eventual treatment of epithelial damage caused by various skin diseases, injuries, or burns.