Buneeva O A, Gnedenko O V, Medvedeva M V, Ivanov A S, Medvedev A E
Institute of Biomedical Chemistry, Moscow, Russia.
Moscow State University, Moscow, Russia.
Biomed Khim. 2016 Nov;62(6):720-724. doi: 10.18097/PBMC20166206720.
The amyloid-beta peptide 1-42 formed during proteolytic processing of the amyloid precursor protein (APP) plays a key role in the development or progression of Alzheimer's disease (AD) and other pathologies associated with formation of protein aggregates in the central nervous system. Recent proteomic profiling of mouse and rat brain preparations by means of beta-amyloid peptide immobilized on Affigel-10 revealed a large group of amyloid-binding proteins (n>80). Many (about 25%) of these proteins were previously identified as isatin-binding proteins. The aim of this study was to validate direct interaction between beta-amyloid peptide and highly purified intact and oxidized peroxiredoxin, M-type pyruvate kinase, alpha-enolase, and the effect of isatin on this interaction. The study performed using SPR-based Biacore 3000 and Biacore X100 biosensors has shown that all the proteins form molecular complexes with immobilized beta-amyloid peptide. The Kd values for these complexes varied from 8.36х10-8 M (peroxiredoxin) to 1.97х10-6 M (alpha-enolase). Oxidative modification of investigated proteins caused opposite effects on complexes of these peptides with beta-amyloid. The endogenous neuroprotector isatin increased dissociation of complexes formed by beta-amyloid peptide with both intact proteins (peroxiredoxin, glyceraldehyde-3-phosphate dehydrogenase) and/or oxidized proteins (peroxiredoxin, pyruvate kinase) used in this study.
淀粉样前体蛋白（APP）蛋白水解加工过程中形成的β-淀粉样肽1-42在阿尔茨海默病（AD）的发生或发展以及其他与中枢神经系统蛋白质聚集体形成相关的病理过程中起关键作用。最近，通过固定在Affigel-10上的β-淀粉样肽对小鼠和大鼠脑提取物进行蛋白质组学分析，发现了一大类淀粉样结合蛋白（n>80）。其中许多蛋白（约25%）先前被鉴定为异吲哚酮结合蛋白。本研究的目的是验证β-淀粉样肽与高度纯化的完整和氧化型过氧化物酶、M型丙酮酸激酶、α-烯醇化酶之间的直接相互作用，以及异吲哚酮对这种相互作用的影响。使用基于表面等离子体共振（SPR）的Biacore 3000和Biacore X100生物传感器进行的研究表明，所有这些蛋白都与固定化的β-淀粉样肽形成分子复合物。这些复合物的解离常数（Kd）值从8.36×10-8 M（过氧化物酶）到1.97×10-6 M（α-烯醇化酶）不等。所研究蛋白的氧化修饰对这些肽与β-淀粉样肽形成的复合物产生相反的影响。内源性神经保护剂异吲哚酮增加了β-淀粉样肽与本研究中使用的完整蛋白（过氧化物酶、甘油醛-3-磷酸脱氢酶）和/或氧化蛋白（过氧化物酶、丙酮酸激酶）形成的复合物的解离。
