利用核磁共振技術研究醣肝素促進 細胞穿透胜肽 ECP32-41 與微胞體的交互作用

Nuclear Magnetic Resonance study of heparin enhanced micelle interaction on novel cell-penetrating peptide, ECP32-41

盧佳吟(Lu, Jia Yin)

指導教授 ： 蘇士哲

國立清華大學/生命科學院/生物資訊與結構生物研究所/碩士(2015年)

https://doi.org/10.6843/NTHU.2015.00266

摘要

人類嗜酸性白血球陽離子蛋白 (human eosinophil cationic protein, hECP) 是一種具有毒性的鹼性蛋白質，是由活化的嗜酸性白血球所分泌來的。ECP能與細胞表面上的硫酸肝素醣蛋白結合，在細胞膜的脂肪筏 (lipid raft) 區域利用胞飲機制進入到支氣管上皮細胞中。先前研究發現ECP中含有三段肝素結合區域(HBRs)，34RWRCK38 (HBR1)、75RSRFR79 (HBR2)、101RPGRR105 (HBR3)，其中ECP序列中的第一段肝素結合區 34RWRCK38 (HBR1)，與肝素醣蛋白結合並促進進入細胞之功能極為相關，同時其他文獻亦指出32NYRWRCKN39序列可與長鏈單尾磷脂微粒(dodecylphosphocholine micelle) 結合。本研究將利用核磁共振技術研究新穎免疫調控胜肽ECP32-41與其點突變胜肽 ECP32-41 W4R以及同源胜肽 EDN32-41 ，鑒定那些胺基酸會與肝素結合，比較這三條胜肽分別與肝素的作用模式。另外，研究ECP32-41序列中的色胺酸與長鏈單尾磷脂微粒結合的情形。

關鍵字

核磁共振 ； 醣肝素 ； 細胞穿透胜肽 ； 微胞體

並列摘要

Human eosinophil cationic protein (hECP) is a heparin-binding ribonuclease secreted by activated eosinophils. ECP is a basic, granule-stored protein known to be cytotoxic toward pathogens and several cell lines involved in the immune innate system. The mechanism of ECP internalization is including HS binding ability and lipid raft-associated micropinocytosis. Previous studies have discovered that the sequence motif 32NYRWRCKNQN41 of ECP was defined to possess in heparin binding and cell penetrating activities, while motif 32NYRWRCKN39 have been proven to bind with dodecylphosphocholine micelle. The binding between ECP32-41 (NYRWRCKNQN) and heparin was previously characterized, but the detail of binding mechanism is still unclear. To achieve the goal, we have used nuclear magnetic resonance (NMR) to evaluate the binding of ECP32-41、ECP32-41 W4R and EDN32-41 and to heparin. Additionally, we also investigated the tryptophan of ECP32-41 leading the interaction with membrane.

並列關鍵字

Nuclear Magnetic Resonance ； heparin ； cell-penetrating peptide ； micelle

參考文獻

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