Licastro F, Sirri V, Trerè D, Davis L J
Department of Experimental Pathology, University of Bologna, Italy.
Dement Geriatr Cogn Disord. 1997 Nov-Dec;8(6):337-42. doi: 10.1159/000106652.
Patients with probable late-onset Alzheimer's disease (l-AD) had higher levels of serum alpha 1-antichymotrypsin (alpha 1-ACT) than those found in patients with vascular dementia (VD) and healthy elderly controls, when assessed by a competitive enzyme-linked immune assay. Serum alpha 1-ACT was also characterized by SDS PAGE electrophoresis. Western blot and computer-assisted optical density reading (OD). Using a polyclonal affinity-purified antibody specific for human alpha 1-ACT, one band with the apparent MW of 60 and another with 180 kD in sera from all subjects were clearly detectable. OD of both alpha 1-ACT bands from patients with l-AD was higher than that from VD patients, the 180-kD form being 2.65 times higher than that observed from patients with VD. Serum levels of other acute phase proteins from l-AD were comparable to those observed in VD patients. A slight but nonstatistical increment of serum IL-6 was noted in patients with l-AD. Serum alpha 1-ACT was purified from 3 of these l-AD patients by a two-step affinity chromatography technique. After Western blot, purified alpha 1-ACT showed two or three different bands which immune-reacted with an antibody specific for alpha 1-ACT. The apparent MWs were 60, 120 and 180 kD. In human sera the serpin was present mainly in a monomeric form, but it could also form SDS stable dimers and trimers. Both monomeric and SDS stable polymeric forms of alpha 1-ACT appeared to be increased in sera from patients with l-AD.
通过竞争性酶联免疫测定法评估时，可能患有迟发性阿尔茨海默病（l-AD）的患者血清α1-抗糜蛋白酶（α1-ACT）水平高于血管性痴呆（VD）患者和健康老年对照者。血清α1-ACT也通过SDS-PAGE电泳、蛋白质印迹法和计算机辅助光密度读数（OD）进行表征。使用针对人α1-ACT的多克隆亲和纯化抗体，在所有受试者的血清中可清楚检测到一条表观分子量为60kD的条带和另一条180kD的条带。l-AD患者α1-ACT两条带的OD均高于VD患者，180kD形式比VD患者高2.65倍。l-AD患者其他急性期蛋白的血清水平与VD患者相当。l-AD患者血清IL-6有轻微但无统计学意义的升高。通过两步亲和层析技术从3例l-AD患者中纯化血清α1-ACT。蛋白质印迹后，纯化的α1-ACT显示出两条或三条不同的条带，它们与α1-ACT特异性抗体发生免疫反应。表观分子量分别为60kD、120kD和180kD。在人血清中，丝氨酸蛋白酶抑制剂主要以单体形式存在，但也可以形成SDS稳定的二聚体和三聚体。l-AD患者血清中α1-ACT的单体形式和SDS稳定的多聚体形式似乎均增加。
