Sonication of proteins causes formation of aggregates that resemble amyloid
Sonication of proteins causes formation of aggregates that resemble amyloid
复制标题
DOI：
10.1110/ps.04831804
复制
发表时间：
2004-11-01
期刊：
影响因子：
8
通讯作者：
Meiering, EM
中科院分区：
文献类型：
--
作者：
Stathopulos, PB;Scholz, GA;Meiering, EM
尽管超声波在医学、工业和研究中得到了广泛的应用，但超声波对蛋白质的影响仍然没有得到充分的表征。我们报道，一系列结构不同的蛋白质的超声波作用导致形成与淀粉样蛋白聚集体相似的聚集体。淀粉样蛋白的形成与多种蛋白质构象紊乱有关，包括阿尔茨海默病、亨廷顿病、帕金森病和普里恩病。聚集体使染料硫代黄素T的荧光有较大的增强，与刚果红结合时呈现绿-金双折射，使刚果红的吸收光谱发生红移。此外，圆二色谱表明，超声诱导的聚集体具有较高的β-含量，具有显著天然α-螺旋结构的蛋白质在聚集体中表现出更多的β-结构。电子显微镜的超微结构分析显示了超声诱导的聚集体的一系列形态，包括直径为5-20 nm的纤维。将预先形成的聚集体添加到非超声蛋白质溶液中，可在加热时加速和增强额外聚集体的形成。染料的结合和结构特征，以及超声波诱导的聚集体形成新聚集体的能力，都与淀粉样蛋白的性质相似。这些结果对超声波在食品、生物技术和医学中的应用，以及对蛋白质聚集和构象紊乱的研究具有重要的意义。
Despite the widespread use of sonication in medicine, industry, and research, the effects of sonication on proteins remain poorly characterized. We report that sonication of a range of structurally diverse proteins results in the formation of aggregates that have similarities to amyloid aggregates. The formation of amyloid is associated with, and has been implicated in, causing of a wide range of protein conformational disorders including Alzheimer's disease, Huntington's disease, Parkinson's disease, and prion diseases. The aggregates cause large enhancements in fluorescence of the dye thioflavin T, exhibit green-gold birefringence upon binding the dye Congo red, and cause a red-shift in the absorbance spectrum of Congo red. In addition, circular dichroism reveals that sonication-induced aggregates have high beta-content, and proteins with significant native alpha-helical structure show increased beta-structure in the aggregates. Ultrastructural analysis by electron microscopy reveals a range of morphologies for the sonication-induced aggregates, including fibrils with diameters of 5-20 nm. The addition of preformed aggregates to unsonicated protein solutions results in accelerated and enhanced formation of additional aggregates upon heating. The dye-binding and structural characteristics, as well as the ability of the sonication-induced aggregates to seed the formation of new aggregates are all similar to the properties of amyloid. These results have important implications for the use of sonication in food, biotechnological and medical applications, and for research on protein aggregation and conformational disorders.