Isoform-specific Binding of Apolipoprotein E to p-Amyloid*
Isoform-specific Binding of Apolipoprotein E to p-Amyloid*
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载脂蛋白 E 与 p-淀粉样蛋白的亚型特异性结合*
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
Frail
中科院分区：
文献类型：
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作者：
Mary Jo LaDutl;Michael;T.;Faldutonll;Arlene;M.;Manellill;Catherine;A.;ReardonS;G. Getz;Donald;E.;Frail
载脂蛋白E（apoE），特别是e4等位基因，与阿尔茨海默病的发病率有遗传联系。ApoE存在于与阿尔茨海默病相关的细胞外老年斑和细胞内神经元缠结中。在体外，apoE已被证明结合P-淀粉样蛋白（AP），淀粉样蛋白前体蛋白的淀粉样蛋白水解产物。为了分析AP和apoE的相互作用，我们使用了人AP-（140）-肽的Western免疫印迹，所述人AP-（140）-肽与来自HEK-293细胞的条件培养基一起孵育，所述HEK-293细胞用人apoE 3或apoE 4（分别是e3和e4等位基因的产物）cDNA转染。非还原SDS-聚丙烯酰胺凝胶电泳显示存在具有AP和apoE免疫反应性的~ 45-kDa复合物。apoE3.AP复合物的水平比apoE 4-AP复合物的水平高约20倍。在pH5.0 - 9.0，肽孵育2分钟-24小时，apoE浓度为5 - 100 μ l，AB浓度为10 μ l-1 μ l时，apoE亚型特异性结合模式得以维持。apoE 3与AP的结合水平较高，这与先前发表的数据相反
Apolipoprotein E (apoE), particularly the e4 allele, is genetically linked to the incidence of Alzheimer’s disease. ApoE is present in the extracellular senile plaques and intracellular neurofibrillary tangles associated with Alzheimer’s disease. In vitro, apoE has been shown to bind P-amyloid (AP), an amyloidogenic proteolytic product of amyloid precursor protein. To analyze the interaction of AP and apoE, we used Western immuno- blotting of humanAP-(l40)-peptide incubated with conditioned medium from HEK-293 cells transfected with either human apoE3 or apoE4 (products of the e3 and e4 alleles, respectively) cDNA Nonreducing SDS-polyac- rylamide gel electrophoresis revealed the presence of an -45-kDa complex with both AP and apoE immunoreac- tivity. The level of the apoE3.AP complex was -20-fold greater than that of the apoE4-AP complex. This apoE isoform-specific binding pattern was maintained from pH 5.0 to 9.0, from 2 min to 24 h of peptide incubation, and at concentrations of apoE from 5 to 100 &ml and of AB from 10 p~ to 1 m ~ . The higher level of apoE3 binding to AP is in contrast to previously published data