使用原子力显微镜现场研究磷脂膜与淀粉样多肽聚集体的相互作用.docVIP

 n 使用原子力显微镜现场研究磷脂膜与淀粉 样多肽聚集体的相互作用# 张瑞洁1，苏芳芳1，张翼1,2** 5 10 （1. 中南大学化学化工学院，长沙 410083； 2. 中南大学粉末冶金国家重点实验室，长沙 410083） 摘要：采用原子力显微镜(AFM)、硫代磺色素(ThT)荧光光谱和紫外可见分光光谱等方法分别 -1 作用机理。通过构筑一个和人体大脑环境近似的体系，以磷脂双层支撑膜来模拟脑细胞的细 胞膜，采用 AFM 现场监测 Aβ42 在磷脂膜诱导下的聚集行为。探索不同环境下浓度为 2 μmol · L -1 的 Aβ42 与磷脂膜间的相互作用。结果表明：低浓度的 Aβ42，无论是酸性、中性偏酸 还是中性偏碱环境下，Aβ42 的自聚集速度都要比相应环境下的磷脂作用下的 Aβ42 的聚集速 度慢，而且聚集体都以球状寡聚体的形态成长。磷脂作用下的 Aβ42，在酸性环境下 Aβ42 聚 集的速度比较快，而且主要聚集为纤维状；中性偏酸环境下 Aβ42 主要聚集成球状的寡聚体， 15 20 25 30 35 40 聚集速度最慢；偏碱性环境下 Aβ42 的聚集速度介于酸性与中性偏酸环境之间，主要聚集状 态为 2-3 nm 高的纤维细丝。 关键词：磷脂；自组装；淀粉样多肽；原子力显微镜 In situ AFM study on the interaction between Beta Amyloid peptide and Phospholipid membrane Zhang Ruijie1, Su Fangfang1, Zhang Yi1,2 (1. Collage of Chemistry and chemical engineer, Center South University, ChangSha 410083; 2. State key laboratory of Powder Metallurgy, Central South University, ChangSha 410083) Abstract: The mission of this thesis is to construct a self-developed matrix system to study the interaction behavior among aggregates and cell membrane and establish an in vitro trustable template to simulate the in vivo reactions among the proteins/peptides and neuron cell take s place in human brain The penetration behavior of β-Amyloid peptide (Aβ) aggregates on supported lipid bilayer membrane surfaces was characterized by in situ AFM. Experimental results indicate that: whether in acidic, neutral or alkaline environment, Aβ42 self gathered speed is slower than the Aβ42 deposited on the lipid support bilayer at low concentration of Aβ42. And the self-assembly aggregates are mainly globular oligomers forms exist. In reviews all the interactions among Aβ42and lipid membrane, the fastest aggegrating speed was achieved at acidic conditions, while main produces are fibrous. At neutral environment, Aβ42 exhibit the slowest gathering speed and the main produce is the globular oligomers in. Aggegrateing speed of Aβ42 in alkaline environment is between that in acidic and neutral environment, and its main aggegrate