Probing Conformational Change of Intrinsically Disordered 伪-Synuclein to Helical Structures by Distinctive Regional Interactions with Lipid Membranes

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• 作者：Shin Jung C. Lee ; Jong Wha Lee ; Tae Su Choi ; Kyeong Sik Jin ; Seonghwan Lee ; Changill Ban ; Hugh I. Kim
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：February 4, 2014
• 年：2014
• 卷：86
• 期：3
• 页码：1909-1916
• 全文大小：359K
• ISSN：1520-6882

文摘

伪-Synuclein (伪-Syn) is an intrinsically disordered protein, whose fibrillar aggregates are associated with the pathogenesis of Parkinson鈥檚 disease. 伪-Syn associates with lipid membranes and forms helical structures upon membrane binding. In this study, we explored the helix formation of 伪-Syn in solution containing trifluoroethanol using small-angle X-ray scattering and electrospray ionization ion mobility mass spectrometry. We then investigated the structural transitions of 伪-Syn to helical structures via association with large unilamellar vesicles as model lipid membrane systems. Hydrogen鈥揹euterium exchange combined with electrospray ionization mass spectrometry was further utilized to understand the details of the regional interaction mechanisms of 伪-Syn with lipid vesicles based on the polarity of the lipid head groups. The characteristics of the helical structures were observed with 伪-Syn by adsorption onto the anionic phospholipid vesicles via electrostatic interactions between the N-terminal region of the protein and the anionic head groups of the lipids. 伪-Syn also associates with zwitterionic lipid vesicles and forms helical structures via hydrophobic interactions. These experimental observations provide an improved understanding of the distinct structural change mechanisms of 伪-Syn that originate from different regional interactions of the protein with lipid membranes and subsequently provide implications regarding diverse protein鈥搈embrane interactions related to their fibrillation kinetics.