LL-37 與細胞膜模擬系統交互作用研究及製備薄膜式生物感測器檢測LL-37

Interaction of LL-37 with Model Membrane Systems and Preparing Lipid Based Biosensor for the Detection of LL-37

鄭安婷(An-Ting Cheng)

指導教授 ： 王鐘毅

大同大學/工程學院/生物工程學系所/碩士(2009年)

摘要

細菌抗藥性演變的速度，遠超過人類新藥的研發。抗菌肽多樣性極高並均有其
獨特性，因此開始受到重視。每年影響上百萬人的泌尿道感染，嚴重時還會併發急
性腎病。保護尿道不受細菌的感染，人和小老鼠的尿道在細菌侵入時都會快速分泌
帶正電荷的抗菌肽LL-37，它可以辨別外來侵入以及天生細胞的不同，讓它們可以
對帶負電荷細菌細胞膜進行破壞，且其抗菌性不受細菌抗藥性的影響，為保護尿道
健康的重要內生長因數。
藉由帶負電荷的脂質組成人工細胞膜模型-Liposome，模擬LL-37 與細菌細胞膜
之間的熱交互關係；以DSC 穩定的提供熱能，使樣品由低溫的Gel-phase 經過相轉
移溫度後呈現Fluid-phase。以及利用螢光探針Laurdan 嵌入Liposome，當Liposome
構形不穩定時，便會使螢光分子接觸到進入的極性水分子，進而放射大量螢光，以
瞭解構形變化。並利用上述之Liposome 與基材製作薄膜式生物感測器，以此脂雙層
膜進行LL-37 感測，發現LL-37 與脂雙層進行混合會產生阻抗（impedance）與相位
（phase angle）之變化。藉此對照無LL-37 的空白組，作為一定性的判斷，希冀日
後能應用於即時監控是否發生泌尿道感染之工具。

關鍵字

抗菌肽 ； LL-37 ； 生物感測器

並列摘要

It’s well known that bacteria have ability to develop antibiotic-resistance in short time after treatment. To find therapeutic agents with different mode of action than conventional antibiotics is a necessity. To meet the above requirement, antimicrobial peptides (AMPs) represent a good alternative for infective antibiotics. AMP LL-37 with positive charges belongs to an immune system that has a capacity to distinguish membrane from different lipids in human. This special property makes LL-37 destroy the negative charged bacteria membranes. Therefore the above mechanism is effective to drug resistance bacteria. Normally bacteria and LL-37 will not exist in urine, except for those patients who suffer urinary tract infection (UTI). Hopefully, a screening biosensor can be made by using the above character.
DSC (Differential Scanning Calorimeter) was used to measure interaction between
LL-37 and liposome that plays a biomembrane role. The stability of the complex can be affected by adding interference salt and urea. In the meantime, the change of liposome structure can be observed by a fluorescence probe on it. Finally, the biosensor was made by immobilizing liposomes on silane coated surface. Testing was made by mixing the sample containing LL-37 on the biosensor plate. The content of LL-37 can be detected and determined by impedance and phase angle variations.

並列關鍵字

biosensor ； antimicrobial peptide ； LL-37

參考文獻

53. 陳春吉，2002。自主性單層膜電極之阻抗分析與其在內毒素檢測上之應用。

2. Agerberth, B., H. Gunne, J. Odeberg, P. Kogner, H. G. Boman, G. H. Gudmundsson.1995. FALL-39, a putative human peptide antibiotic, is cysteine-free and expressed in bone marrow and testis. Proc Natl Acad Sci U S A. 92:195-9.

4. Anne, L. 1993. Plant. Self -Assembled Phospholipid/Alkanethiol Biomimetic Bilayers on Gold. Langmuir. 9:2764-2767.

7. Boman, H. G. 2003. Antibacterial peptides: basic facts and emerging concepts. J InternMed. 254:197-215.

8. Britta, L. S. 1996. Electrochemistry at Ultrathin Organic Films at Planar Gold Electrodes. Langmuir.12:3305-3314.