The Effects Of Ultraviolet Irradiation On Aβ-Cu²⁺/Zn²⁺Aggregates Stability And Reactive Oxygen Species Production

Alzheimer’s disease, also known as senile dementia, is characterized by major pathological deposition of extracellular senile plaques, the neurofibrillary tangles of nerve cells and synapse loss. Alzheimer’s disease as a neurodegenerative disease, and Aβ aggregation and related reactive oxygen species generation. On the basis of preliminary work on the Task Force, a more systematic study of the effects of UV irradiation on Aβ-Cu2+/Zn2+aggregates stability and reactive oxygen species generated.The results of this paper are as follows:Denaturing polyacrylamide gel electrophoresis results showed that A042, Aβ-Cu+/Zn+aggregates cultured to form tetramers, hexamers, and high molecular weight(greater than100kD) aggregates. After UV irradiation, aggregates depolymerization obvious. Circular dichroism UV irradiation test results show that makes Aβ42, Aβ-Cu2+/Zn2+secondary structure changed to some extent. By the β-sheet conformation gradually transformed into random coil conformation. The use of electron paramagnetic resonance(electron paramagnanetic resonance, EPR) were measured in the dark and UV irradiation conditions Aβ-Cu2+/Zn2+aggregates of reactive oxygen species. Join in the system FeSO4, FeSO4and Aβ42-Cu+produced by H2O2reaction of hydroxyl radical(OH), OH and system reaction solvent DMSO methyl radical(CH3). EPR detected CH3, indicate the system produces reactive oxygen species H2O2. These results suggest that UV irradiation of Aβ42, AP-Cu2+/Zn2+aggregates stability of the body, secondary structure, the generation of reactive oxygen species are affected.Denaturing polyacrylamide gel electrophoresis experiments observed after the addition of a metal chelator, dark conditions Aβ-Cu2+/Zn2+aggregates depolymerization effect is not obvious, but after UV irradiation depolymerization obvious. Circular dichroism showed that the test results, the metal chelating agent is added to the FC-11Aβ42, Aβ-Cu2+/Zn2+aggregates little influence on the secondary structure. EPR results showed that Aβ42-Cu2+-FC-11in the dark and UV irradiation conditions are produced H2O2, Aβ42-Cu2+-FC-11-1to produce H2O2under dark conditions, after UV irradiation does not produce H2O2. The Aβ42-Zn2+-FC-11/FC-11-1in the dark and UV irradiation conditions are not produced H2O2.