Binding of cystatin C to Alzheimer's amyloid β inhibits in vitro amyloid fibril formation
Binding of cystatin C to Alzheimer's amyloid β inhibits in vitro amyloid fibril formation
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DOI：
10.1016/j.neurobiolaging.2003.11.006
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发表时间：
2004-09-01
影响因子：
4.2
通讯作者：
Levy, E
中科院分区：
文献类型：
--
作者：
Sastre, M;Calero, M;Levy, E
半胱氨酸蛋白酶抑制剂Cystatin C与淀粉样蛋白β（Abeta）在阿尔茨海默病（AD）患者脑实质和血管淀粉样蛋白沉积物中的共定位可能反映了Cystatin C参与环状体形成。因此，我们试图确定胱抑素C与Abeta的关联。转染培养细胞的免疫荧光分析表明，细胞内和细胞表面上的胱抑素C和β淀粉样前体蛋白（β APP）的共定位。免疫沉淀的细胞裂解物或培养基蛋白的Western印迹分析揭示了胱抑素C与全长β APP和分泌的β APP（sbetaAPP）的结合。β APP的缺失突变体将β APP内的胱抑素C结合位点定位于Abeta区域。胱抑素C与β APP的结合导致sbetaAPP增加，但不影响分泌的Abeta水平。胱抑素C和Abeta的结合分析表明胱抑素C与Abeta（1-42）和Abeta（1-40）之间具有特异性、可饱和和高亲和力结合。值得注意的是，半胱氨酸蛋白酶抑制剂C与All结合导致对Abeta原纤维形成的浓度依赖性抑制。(C)2003年爱思唯尔公司All rights reserved.
The colocalization of cystatin C, an inhibitor of cysteine proteases, with amyloid beta (Abeta) in parenchymal and vascular amyloid deposits in brains of Alzheimer's disease (AD) patients may reflect cystatin C involvement in annyloidogenesis. We therefore sought to determine the association of cystatin C with Abeta. Immunofluorescence analysis of transfected cultured cells demonstrated colocalization of cystatin C and beta amyloid precursor protein (betaAPP) intracellularly and on the cell surface. Western blot analysis of immunoprecipitated cell lysate or medium proteins revealed binding of cystatin C to full-length betaAPP and to secreted betaAPP (sbetaAPP). Deletion mutants of betaAPP localized the cystatin C binding site within betaAPP to the Abeta region. Cystatin C association with betaAPP resulted in increased sbetaAPP but did not affect levels of secreted Abeta. Analysis of the association of cystatin C and Abeta demonstrated a specific, saturable and high affinity binding between cystatin C and both Abeta(1-42) and Abeta(1-40). Notably, cystatin C association with All results in a concentration-dependent inhibition of Abeta fibril formation. (C) 2003 Elsevier Inc. All rights reserved.