Establishment of assay system for beta-site APP cleaving enzyme activity and evaluation of inhibitors

• Main Authors: Chiung-Yi Huang, 黃瓊誼
• Other Authors: 孔繁璐
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/15405481940629533517

碩士 === 國立臺灣大學 === 藥學研究所 === 92 === Alzheimer’s disease (AD) is a progressive neurodegenerative disorder often associated with elderliness and adult Down’s syndrome individuals. It is characterized pathologically of the intraneuronal neurofibrillary tangles (NFT) and the extracellular senile plaques (SP) from the brains of AD patients. The amyloid precursor protein (APP) is processed by ��-site APP cleaving enzyme (BACE) and γ-secretase to produce the A�� peptide, the major protein component of the senile plaque. It has been noted to develop ways to inhibit Aβ formation because of the neurotoxicity of Aβ aggregation. One way to decrease the level of Aβ is to inhibit the enzyme BACE. A fluorescence resonance energy transfer (FRET) approach, in which a sensitive fluorogenic peptide substrate was used, was utilized to evaluate the cleavage activity of BACE. This method can also be used to monitor the change of BACE activity in the presence of inhibitors. The IC50 of the standard inhibitor P10-P4’ StatVal was determined to be 90.9 nM using this method. No appreciable inhibition activity against BACE was observed for a series of synthetic compounds derived from a known metal chelator. Interestingly, one of these compounds enhanced BACE activity instead. The effect of this compound and metal ions to the BACE activity were therefore investigated. In consequence, this is a fast and convenient assay system to screen BACE inhibitors and to characterize BACE catalysis kinetically, and eventially to know more about the pathologic pathway of Alzheimer’s disease.