β-淀粉样多肽1-42(Aβ_(42))多克隆抗体的制备及其鉴定

Preparation and Characterization of Polyclonal Antibody to β-Amyloid (1-42) Peptide

目的 :β -淀粉样多肽 1 - 4 2 (Amyloidβ1 -42 ,简称Aβ42 )是存在于阿尔茨海默病 (Alzheimer′sDis ease,AD)患者脑组织中的特异病理改变之物 ,同时它在AD患者的脑积液及血浆中有所改变。我们制备Aβ42多克隆抗体及其建立测定方法 ,是希望找到一个特异性鉴定AD的生物指标。方法 :将Aβ42 多肽与匙孔虫戚血蓝蛋白 (KLH)偶联 ,免疫新西兰白兔从而产生抗 -Aβ42 多克隆抗体。此特异性抗体可用于ELISA、Western印迹法和免疫组织化学的方法中 ,并可测定AD脑组织中的特异性淀粉样沉淀物。结果 :通过免疫组织化学法鉴定此抗 -Aβ42 多克隆抗体 ,结果显示在AD患者的脑组织淀粉样沉淀物中呈阳性。同时应用Western印迹法对Aβ42 抗体进行了鉴定 ,结果显示Aβ42 多肽的分子量与Aβ42 多肽标准的 4 5kDa分子量相一致。结论 :我们所制备的Aβ42 多克隆抗体能与Aβ42 抗原呈特异性结合 ,这就为研究淀粉样前体蛋白 (APP)

Objective β-amyloid(1-42) peptide (Aβ 42 ) has been identified as a major specific feature in the pathology of Alzheimer's disease (AD). Its levels in the cerebrospinal fluid (CSF) and blood deviate from normal in AD patients. We developed a polyclonal antibbody to Aβ 42 to identify Aβ 42 peptide, as a specific biomarker for AD. Methods New Zealand rabbits were immunized with synthetic Aβ 42 peptide coupled to keyhole limpet haemocyanin (KLH) for the production of the polyclonal anti-Aβ 42 antibody. The specificity of the anti-Aβ 42 antibody to detect the Aβ 42 peptide in the amyloid deposits in brain tissues of AD patients was assessed by ELISA, Western blot and immunohistochemistry. Results In immunohistochemical studies the polyclonal anti-Aβ 42 antibody showed strong positive staining of amyloid deposits in brain tissues from AD patients. Western blotting revealed that the anti-Aβ 42 antibody detected the 4 5kDa antigenic peptide. Conclusion The anti-Aβ 42 antibody we develop specifically recognizes the native peptide. It will serve as a useful tool for elucidation of the significance of Aβ 42 peptide in physiological and pathophysiological environment.