Preparation And Characterization Of β-amyloid Oligomers

Alzheimer Disease(AD)is a central nervous system degenerative disease.The pathological hallmarks of AD are neuritic plaques and neurofibrillary tangles.In recent years,along with the continuous renewal of β-amyloid protein hypotheses,a growing number of the experimental results show that amyloid protein deposition is the result of AD pathogenesis.However amyloid oligomers is the chief culprit of AD pathogenesis.For purpose of a deeper understanding of the molecular mechanism of β-amyloid protein misfolding and aggregation in the molecular level,understanding the molecular structures of β-amyloid oligomers is pressing.Solid nuclear magnetic resonance technique is the most powerful tool.However,solid nuclear magnetic resonance technique of analyzing protein structure demand higher.It needs a lot of samples with better uniformity.Therefore it is particularly important to preparate β-amyloid oligomers of meeting the requirements in vitro.In this research,following is the brief introduction:(1)β-amyloid(1-40)is acquiredCombined molecular cloning and protein expression and purification techniques to successfully obtain pure β-amyloid(1-40)in an E.coli cell.(2)Preparation and characterization of β-amyloid(1-40)oligomersWe captured β-amyloid(1-40)oligomers in solution environment,through the adoption of low temperature and low salt and addition inhibitors,metal ions.The β-amyloid(1-40)oligomers were detected by electrophoresis,fluorescence spectroscopy,circular dichroism and transmission electron microscopy.We found β-amyloid(1-40)oligomers which adopt globulomer formation and 15nm-35 nm in diameter.(3)The molecular mechanism of inhibitors,metal on β-amyloid(1-40)aggregationOn the basis of task 2,we researched molecular mechanism which β-amyloid(1-40)engaged in interaction with inhibitors,metal ions by solution-state nuclear magnetic resonance.Further we confirm the complexity of the β-amyloid protein aggregation.So that,we provide a theoretical basis which design drugs to inhibit aggregation dynamics process.Therefore treatment and prevention of AD has very important value and significance.