抗菌小蛋白藉由吸附在細胞膜表面，進而產生穩定的孔洞來殺死細菌及微生物，其機制正被廣泛地研究，也有數種理論模型被提出。 本文將使用被廣為研究的蜂毒蛋白（melittin）和不同長度的磷脂質（Di22：1PC 和Di20：1PC）所製備的巨型微胞（GUVs）作用，並結合玻璃微管吸引法（Aspiration method）與螢光顯微鏡技術（Fluorescence microscopy），測量巨型微胞所產生的表面積增加ΔA，來與多片層X光繞射（Lamellar X-ray Diffraction, LXD）、指向性圓極化雙光譜技術（Oriented Circular Dichroism, OCD）的結果比較。 實驗結果顯示在溶液中蜂毒蛋白與巨型微胞胞膜作用的確會造成面積延展，且在開始形成孔洞時，巨型微胞胞膜面積延展率會達到一門檻值 。實驗測量結果如下：長的脂質分子Di22：1PC胞膜面積延展率門檻 ≒0.08；而短的脂質分子Di20：1PC胞膜面積延展率門檻 ≒0.06；此結果與已發表的X光片層繞射及圓極化雙光譜技術實驗結果吻合。 本論文提供一項新的且有效的技術來觀察在溶液中抗菌小蛋白與巨型微胞的作用；並進一步證明不論在溶液中巨型微胞或基底上多片層膜系統中，抗菌小蛋白吸附在胞膜表面，使面積延展，是膜上孔洞形成的機制。 Peptide binding in cell membranes can induce stable pores to kill the cell. This function has been studied extensively, yet few fundamental questions have not been answered, in particularly the dependence of peptide activity on the environment. In this thesis, we study melittin interacting with giant unilamellar vesicle (GUV), the membrane in aqueous environment. The result was compared to the lamellar phase membrane on substrate, which has been studied by lamellar X-ray diffraction (LXD) and oriented circular dichroism (OCD). The aspiration method and fluorescence microscopy were combined to measure the membrane surface expansion ΔA. The result revealed that the membrane surface expansion ratio arrives at critical value , once pores are formed. Quantitatively, ≒0.08 for long chain lipid Di22：1PC whereas ≒0.06 for short chain lipid Di20：1PC, in agreement with the result for lamellar phase membrane studied LXD and OCD. Our study provides a new useful technology to observe the interaction of peptides with lipids. And furthermore it proves that no matter membrane in aqueous environment or in lamellar phase on substrate, peptides have the same activities, namely, expanding membrane surface and inducing pores.
