Amyloid-β is an antioxidant for lipoproteins in cerebrospinal fluid and plasma
Amyloid-β is an antioxidant for lipoproteins in cerebrospinal fluid and plasma
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DOI：
10.1016/s0891-5849(00)00458-5
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发表时间：
2001-01-01
影响因子：
7.4
通讯作者：
Beisiegel, U
中科院分区：
文献类型：
--
作者：
Kontush, A;Berndt, C;Beisiegel, U
淀粉样蛋白- β (A β)肽是老年斑的主要成分，也是阿尔茨海默病（AD）的标志，通常由神经元分泌，在脑脊液（CSF）和血浆中存在低浓度，与脂蛋白有关。然而，A β分泌的生理作用尚不清楚。本研究表明，在生物体液中测量的浓度（0.1-1.0 nM）下，A β(1-40)强烈抑制脑脊液脂蛋白和血浆低密度脂蛋白（LDL）的自氧化。在较高浓度的肽，其抗氧化作用被取消。当加入摩尔过量的铜时，β(1-40)也抑制铜催化的LDL氧化，但不影响由盐引发剂诱导的氧化。其他A β肽也具有抗氧化活性，顺序为A β (1-40) > A β (1-42) > A β(25-35)，而A β(35-25)无活性。这些数据表明A β(1-40)可能在脑脊液和血浆脂蛋白中作为一种生理抗氧化剂，通过螯合过渡金属离子发挥作用。(C) 2000 Elsevier Science Inc.；
Amyloid-beta (A beta) peptide, a major constituent of senile plaques and a hallmark of Alzheimer's disease (AD), is normally secreted by neurons and can be found in low concentrations in cerebrospinal fluid (CSF) and plasma, where it is associated with lipoproteins. However, the physiological role of A beta secretion remains unknown. Here we show that at the concentrations measured in biological fluids (0.1-1.0 nM), A beta (1-40) strongly inhibits autooxidation of CSF lipoproteins and plasma low density lipoprotein (LDL). At higher concentrations of the peptide its antioxidant action was abolished. A beta (1-40) also inhibited copper-catalyzed LDL oxidation when added in molar excess of copper, but did not influence oxidation induced by an ate-initiator. Other A beta peptides also possessed antioxidant activity in the order A beta (1-40) > A beta (1-42) > A beta (25-35), whereas A beta (35-25), was inactive. These data suggest that A beta (1-40), may act as a physiological antioxidant in CSF and plasma lipoproteins, functioning by chelating transition metal ions. (C) 2000 Elsevier Science Inc.