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Title: 1. 立體化學與藥物活性探討:類石膽酸衍生物與唾液酸轉移酶抑制劑 2. 藥物-生物素的結合與免疫沉澱應用
Authors: 李文山
Keywords: 石膽酸
lithocholic acid
sialyltransferase inhibitors
applications in immunoprecipitation
Issue Date: 2011
Abstract: 第一部分:立體化學與藥物活性探討:類石膽酸衍生物與唾液酸轉移酶抑制劑 石膽酸以及其衍生物以被證實是唾液酸轉移酶抑制劑,而且在MDA-MB-231乳癌細胞具有抗轉移功效。本論文探討,改變石膽酸3號羥基位相合成出類石膽酸與類石膽酸衍生物,並從Wound healing assay得知化合物3、11、17、20、23、25、27具有抗癌細胞轉移的能力,並藉由HPLC assay證明化合物25、27對唾液酸轉移酶α-2,6(N)-ST具有抑制效果。所以,類石膽酸衍生物不會因改變3號羥基位,而失做為唾液酸轉移酶抑制劑的能力。 第二部分:藥物-生物素結合物與免疫沉澱應用 鏈霉親和素與生物素間具有很強的親和力,生醫檢驗上廣泛利用此性質進行蛋白質的免疫沉澱純化。本論文將藥物SK228與NBD-Asp-LA,分別修飾上生物素,藉此探討藥物可能的生物機制。化合物43因生物活性下降太多,無法藉由免疫沉澱純化出蛋白質。化合物49經Wound healing assay與HPLC assay,確定化合物49仍然具有生物活性,可以提供免疫沉澱純化蛋白質。
Part I: Impact of stereochemistry in biological properties of sialyltransferase (ST) inhibitors: Iso-lithocholic acid analogues Lithocholic acid analogues, a series of sialyltransferase inhibitors, are later confirmed by our laboratory to suppress cancer metastasis in breast cancer cells and lung cancer cells in vitro and in vivo. Here, reversal of stereochemistry of hydroxyl group in C3 position of lithocholic acid, iso-lithocholic acid, is developed and synthesized. Biological evaluation of iso-lithocholic acid and its analogues (3、11、17、20、23、25、27) show that most of them effectively suppress metastasis of breast cancer cell using wound healing assay. Especially, compound 25 and 27 show ability of inhibiting α-2,6(N)-ST activity by the method of HPLC assay, developed in our laboratory previously. In summary, iso-lithocholic acid analogues with opposite stereochemistry (versus lithocholic acid) exhibit important therapeutic values relating not only to inhibitory manner of ST but also to anti-metastatic behaviors of cancer cell lines. Part II: Biotin-conjugated anticancer agents and their applications in immunoprecipitation In cell biology, utilization of high affinity between streptavidin and biotin is commonly used in protein targeting, purification and enhancement. We modify and prepare anticancer agents, SK228 and NBD-Asp-LA, by conjugation with biotin and use them to identify and recognize their biological partners, the proteins. Due to the reduction of antiproliferative activity of biotin-conjugated SK228, we cannot detect any proteins after immunoprecipitation assay. On the other hand, biotin-conjugated NBD-Asp-LA shows the effective inhibition potency against sialyltransferase and its application to catch biological target protein will be evaluated later using immunoprecipitation assay.
Other Identifiers: GN0698420264
Appears in Collections:學位論文

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