表面帶有特定抑制劑的奈米粒子在生醫應用上越來越被常使用，尤其是目標蛋白質的鑑定、分離與增強。而在這些應用當中，蛋白質的吸附與鑑定是令人注目的領域，但在奈米生醫應用上仍有障礙需要克服。為了克服這些問題，我們需要在奈米粒子的表面結合對目標蛋白質有高親和力的分子，例如唾液酸轉移酶抑制劑。 我們實驗室以石膽酸為主體發展出一系列對唾液酸轉移酶有抑制效果的衍生物，其中以接有NBD-L-天冬胺酸 (NBD-L-Asp)還有L-天冬胺酸 (L-Asp)的石膽酸衍生物效果最好。我們以這兩個石膽酸唾液酸轉移酶抑制劑作為探針，經由click反應接上磁性奈米粒子成為磁性奈米探針，即化合物15 還有化合物16。 在探針測試實驗當中，我們以磁性奈米探針對α2,3(N)-sialyltransferase 進行in vitro 實驗，利用SDS-PAGE 上的蛋白質訊號 (38 kDa)還有LC MS-MS 在蛋白質體學上的輔助可以證明我們所合成出來的磁性奈米探針，化合物15 及化合物16 的確有抓取唾液酸轉移酶的能力。我們也使用化合物15 及化合物16 對打破的癌細胞 (crude cell lysate)進行in vitro 實驗，發現我們所合成的磁性奈米探針亦可以從打破的癌細胞當中抓取蛋白質，並且在對癌細胞的in vitro 實驗當中我們發現數種令我們感興趣的蛋白質，而其中最讓我們感興趣的是Talin。我們所合成出來的唾液酸轉移酶抑制劑跟Talin 還有癌細胞轉移之間的關係需要我們再進一步的研究探討。 Nanoparticles bearing surface-conjugated specific inhibitors are increasingly being utilized for a number of bio-applications including identification, separation and enhancement of desired proteins. These attractive bio-applications involve specific adsorption and recognition; however, these are the major hindrances for nanobiotechnology. To solve this question, we have investigated the effect of nanoparticle surface displaying high affinity molecules, such as sialyltransferase inhibitors. Maintaining a reasonable affinity toward desired protein is generally a prerequisite for proper design of nanoparticle-conjugated specific inhibitors. We prepared sialyltransferase inhibitors, lithocholic acid derivatives with L-Asp or NBD-L-Asp moiety, which have IC50 values at micromolar ranges. Next, magnetic nanoparticle (iron oxide)-conjugated lithocholic acid derivatives, compounds 15~16, were synthesized via click chemistry. Herein, we demonstrated that compounds 15~16 have the ability to identify, separate and enhance binding to the target alpha-2,3(N)-sialyltransferase, a glycol- and membrane-bound protein. The protein band (38 kDa) on SDS-PAGE derived from rat was confirmed by LC MS-MS analysis and proteomics searching. Extending these studies to crude cell lysate in vitro experiment, we found several interesting proteins including talin. Further investigation of talin toward metastasis in cancer is in progress.
