Ahn Jung Sun, Lee Jung-Ho, Kim Je-Hoon, Paik Seung R
School of Chemical and Biological Engineering, College of Engineering, Seoul National University, Kwanak-Ku, Seoul 151-744, Korea.
Anal Biochem. 2007 Aug 15;367(2):259-65. doi: 10.1016/j.ab.2007.05.023. Epub 2007 May 26.
Amyloidosis producing insoluble fibrillar protein aggregates is the common pathological feature of various neurodegenerative disorders such as Parkinson's and Alzheimer's diseases in which alpha-synuclein and amyloid beta/A4 protein (Abeta) participate to form Lewy bodies and senile plaques, respectively. To develop a novel analytical tool for amyloidosis, resveratrol, the major phenolic constituent of red wine and isolatable from grapevines, was employed to monitor the amyloids of alpha-synuclein and Abeta. Specific interaction to the amyloids enhanced the intrinsic fluorescence of resveratrol at 395 nm with an advent of new shoulder peak at 440 nm following an excitation at 320 nm. An increase in the resveratrol binding fluorescence was proportional to the quantity of amyloids. Typical sigmoidal kinetics of the amyloidosis of alpha-synuclein assessed with the thioflavin-T binding fluorescence or the beta-sheet content was fully reproduced by the resveratrol binding fluorescence. The resveratrol binding to the amyloids became saturated as the dye concentration increased, whereas the enhanced thioflavin-T binding fluorescence was quenched by the unbound thioflavin-T at the high dye concentration. Because resveratrol does not require any adjustment of the amyloid/dye ratio to obtain optimal amyloid binding fluorescence, and it exerts a higher quantum yield than does thioflavin-T, resveratrol is suggested to be a specific and more reliable fluorescent probe to determine the amyloids quantitatively.
产生不溶性纤维状蛋白聚集体的淀粉样变性是各种神经退行性疾病的常见病理特征，如帕金森病和阿尔茨海默病，其中α-突触核蛋白和淀粉样β/A4蛋白（Aβ）分别参与形成路易小体和老年斑。为了开发一种用于淀粉样变性的新型分析工具，白藜芦醇（红酒的主要酚类成分，可从葡萄藤中分离得到）被用于监测α-突触核蛋白和Aβ的淀粉样蛋白。与淀粉样蛋白的特异性相互作用增强了白藜芦醇在395nm处的固有荧光，在320nm激发后，在440nm处出现新的肩峰。白藜芦醇结合荧光的增加与淀粉样蛋白的数量成正比。用硫黄素-T结合荧光或β-折叠含量评估的α-突触核蛋白淀粉样变性的典型S形动力学通过白藜芦醇结合荧光得到了完全重现。随着染料浓度的增加，白藜芦醇与淀粉样蛋白的结合达到饱和，而在高染料浓度下，未结合的硫黄素-T会淬灭增强的硫黄素-T结合荧光。由于白藜芦醇不需要调整淀粉样蛋白/染料比例即可获得最佳的淀粉样蛋白结合荧光，并且其量子产率高于硫黄素-T，因此白藜芦醇被认为是一种用于定量测定淀粉样蛋白的特异性更强、更可靠的荧光探针。
