基于Aerolysin纳米孔道的单个β-淀粉样多肽N-端片段分析  

Analysis of N-Terminal Fragment ofβ-Amyloid Peptides Using an Aerolysin Nanopore

作　　者：陈天泽 胡方舟 林绪波 应佚伦 邹爱华 CHEN Tianze;HU Fangzhou;LIN Xubo;YING Yilun;ZOU Aihua(College of Chemistry and Materials Science,Shanghai Normal University,Shanghai 200237,China;School of Chemical and Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China;School of Medical Science and Engineering,Beihang University,Beijing 100191,China;State Key Laboratory of Life Analytical Chemistry,School of Chemistry and Chemical Engineering,Nanjing University,Nanjing 210023,China)

机构地区：[1]上海师范大学化学与材料科学学院,上海200237 [2]华东理工大学化学与分子工程学院,上海200237 [3]北京航空航天大学医学科学与工程学院,北京100191 [4]南京大学化学化工学院,生命分析化学国家重点实验室,南京210023

出　　处：《高等学校化学学报》2024年第11期200-208,共9页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:22334006)资助。

摘　　要：淀粉样蛋白(β-amyloid,Aβ)引起的淀粉样蛋白异常沉积被认为是诱发阿尔茨海默症的因素之一.与人类不同,啮齿动物较少出现这类特征性病变.与人类Aβ相比,啮齿动物Aβ的第5,10和13位氨基酸由Arg,Tyr和His分别变为Gly,Phe和Arg.本文采用分子动力学模拟和Aerolysin纳米孔道单分子分析技术对人类Aβ_(1—15)和啮齿动物Aβ_(1—15)的结构差异进行研究.实验结果表明,与人类Aβ_(1—15)相比,啮齿动物Aβ_(1—15)穿过纳米孔道时具有更低的阻断频率和能垒,证明了Aerolysin纳米孔道可以辨别具有细小结构差异的Aβ多肽分子.本文以硫酸盐K_(2)SO_(4)作为糖胺聚糖(Glycosaminoglycans,GAGs)的简化模型,对Aβ_(1—15)与硫酸根离子的相互作用进行研究.统计分析显示,两种多肽均能与硫酸根离子结合,降低它们被纳米孔道捕获的频率,人类Aβ_(1—15)的捕获频率降低25%,啮齿动物Aβ_(1—15)的捕获频率降低59%.然而,加入硫酸根离子后,两种多肽阻断时间的变化存在明显差异,与未加入硫酸根时相比,人类Aβ_(1—15)的阻断时间延长了14%,啮齿动物Aβ_(1—15)的阻断时间则缩短了7%.由实验结果推测,两种多肽不同的序列和构象导致它们与硫酸根离子结合的方式和强度不同,对过孔行为产生了不同影响.本文研究结果对于筛选用于阿尔茨海默症治疗的小分子抑制类药物具有参考价值.Alzheimer’s disease(AD)is one of the most common diseases caused by multiple neurodegenerative protein misfolding and aggregation disorders.Abnormal deposition of amyloid protein caused byβ-amyloid(Aβ)peptides has been suggested as a possible predisposing factor for Alzheimer’s disease.Unlike human Aβpeptide,rodent Aβpeptide rarely has these characteristic lesions.The difference between rodent Aβpeptide and human Aβpeptide is that the 5th,10th and 13th amino acids(Arg,Tyr,His)are replaced by Gly,Phe and Arg,respectively.In this study,molecular dynamics simulation and nanopore-based single molecule detection technology were used to study the structural differences between human Aβ_(1—15)and rodent Aβ_(1—15).The experimental results show that rodent Aβ_(1—15)has lower blocking frequency and energy barrier when passing through nanopore than human Aβ_(1—15),which proves that aerolysin nanopore can distinguish Aβ_(1—15)with small structural differences.Furthermore,the interaction between Aβ_(1—15)and sulfate ion was studied by using sulfate K_2SO_(4)as a simplified model of glycosaminoglycan(glycosaminoglycans,GAGs).Statistical analysis showed that both peptides could bind to sulfate ions and reduce their capture frequency by aerolysin nanopore,reducing the capture frequency of human Aβ_(1—15)by 25%and rodent Aβ_(1—15)by 59%.However,after the addition of sulfate ion,there was a significant difference in the dwell time of the two peptides.Compared with the results in the absence of sulfate,the dwell time of human Aβ_(1—15)increased by 14%and that of rodent Aβ_(1—15)decreased by 7%.It is inferred from the experimental results that the different sequences and conformations of the two peptides lead to different binding ways and binding intensity to sulfate ions,which have different effects on the translocation behavior.This study is helpful to better screen small molecular inhibitors and further promote the diagnosis and treatment of Alzheimer’s disease.

关 键 词：Β-淀粉样蛋白 气单胞菌溶素 多肽单分子分析 生物纳米孔道 

分 类 号：O657[理学—分析化学]