Sparkman D R, Goux W J, Jones C M, White C L, Hill S J
University of Texas Southwestern Medical Center, Department of Pathology, Dallas 75235-9072.
Biochem Biophys Res Commun. 1991 Dec 16;181(2):771-9. doi: 10.1016/0006-291x(91)91257-d.
The core structures of sodium dodecyl sulfate extracted, pronase digested paired helical filaments of Alzheimer disease were solubilized by heating in dimethyl sulfoxide. Electron microscopy revealed that after heating in dimethyl sulfoxide, intact paired helical filaments were no longer present in the dimethyl sulfoxide soluble fractions or in the insoluble lipofuscin-containing fractions. Enzyme-linked immunosorbent assays of the various fractions with the monospecific antibody A128 to paired helical filaments demonstrated 96% of the immunoreactivity to be in the dimethyl sulfoxide soluble fraction, and only 4% in the dimethyl sulfoxide insoluble fractions. Lyophilization of the dimethyl sulfoxide soluble supernatant and resuspension in water failed to reassociate the paired helical filaments, but did result in an insoluble precipitate. Analysis of the dimethyl sulfoxide solubilized paired helical filament fraction by nuclear magnetic resonance revealed it to be composed of glycolipid in a form that was distinct from similar fractions isolated from normal aged control brains. The aggregation of an altered glycolipid to form paired helical filaments in Alzheimer disease could explain their insolubility.
用十二烷基硫酸钠提取、链霉蛋白酶消化的阿尔茨海默病配对螺旋丝的核心结构，通过在二甲基亚砜中加热而溶解。电子显微镜显示，在二甲基亚砜中加热后，完整的配对螺旋丝不再存在于二甲基亚砜可溶部分或含脂褐素的不溶部分中。用针对配对螺旋丝的单特异性抗体A128对各个部分进行酶联免疫吸附测定表明，96%的免疫反应性存在于二甲基亚砜可溶部分，而仅4%存在于二甲基亚砜不溶部分。将二甲基亚砜可溶上清液冻干并重新悬浮于水中，未能使配对螺旋丝重新缔合，但确实产生了一种不溶性沉淀。通过核磁共振分析二甲基亚砜溶解的配对螺旋丝部分，发现其由糖脂组成，其形式与从正常老年对照大脑中分离出的类似部分不同。在阿尔茨海默病中，一种改变的糖脂聚集形成配对螺旋丝可以解释它们的不溶性。
