\r董晓燕，董旭婷，孟 杰\r
\r
AuthorsHTML:\r董晓燕，董旭婷，孟 杰\r
\r
AuthorsListE:\rDong Xiaoyan，Dong Xuting，Meng Jie\r
\r
AuthorsHTMLE:\rDong Xiaoyan，Dong Xuting，Meng Jie\r
\r
Unit:\r天津大学化工学院，天津 300354\r
\r
Unit_EngLish:\rSchool of Chemical Engineering and Technology，Tianjin University，Tianjin 300354，China\r
\r
Abstract_Chinese:\r\r由于β-淀粉样蛋白(amyloid β-protein，Aβ)的聚集是阿尔茨海默症(Alzheimer’s disease，AD)发病机制中的\r关键过程，而金属离子Cu\r²⁺\r存在下的Aβ 的聚集速率加快，且Cu\r²⁺\r本身会促进活性氧(ROS)的产生，增加神经毒\r性，因此开发既能螯合Cu\r²⁺\r又能抑制Aβ 聚集的双功能抑制剂非常重要．本文将金属螯合三肽(SSH)和Aβ 聚集七\r肽抑制剂Ac-LVFFARK-NH\r₂\r(LK7)相组合，设计合成了新的双功能Aβ 聚集十肽抑制剂SSHLVFFARKNH\r₂\r(SK10)．通过硫代黄素T(ThT)荧光实验、聚集动力学实验、原子力显微镜检测(AFM)、等温滴定量热和MTT\r细胞毒性测定等研究了SK10 对Cu\r²⁺\r存在下Aβ 聚集的抑制和解聚作用以及细胞毒性的抑制作用．实验结果表明：\rSK10 不仅可以抑制Cu\r²⁺\r存在下的Aβ\r₄₀\r聚集(ThT 荧光强度降低了60%)，随着SK10 浓度的提高使Aβ40纤维逐渐减\r少，还能降低Cu\r²⁺\r存在下Aβ\r₄₀\r 聚集产生的细胞毒性，使细胞活性恢复至90%以上；同样，SK10 对Cu\r²⁺\r存在下的\rAβ₄₂ 聚集也有抑制作用．由于SK10 对Cu\r²⁺\r具有较强的特异性亲和力(K\r_d\r＝0.03 μmol/L)，能够螯合Cu\r²⁺\r-Aβ\r₄₀\r 复合\r物中的Cu\r²⁺\r，因此能抑制由Cu\r²⁺\r催化产生的活性氧(ROS)对细胞的毒性．进一步研究表明SK10 还可解聚形成的\rCu\r²⁺\r-Aβ\r₄₀\r 聚集体，使已形成的Cu\r²⁺\r-Aβ\r₄₀\r 聚集体消失，缓解其产生的细胞毒性，使细胞活性提高到90%．以上研究\r结果不但体现了SK10的药用潜力，也为今后设计和开发金属螯合Aβ 聚集双功能抑制剂提供了思路．\r\r
\r
Abstract_English:\rThe aggregation of amyloid β-protein (Aβ) is an important process in the pathogenesis of Alzheimer’s disease(AD). The aggregation rate of Aβ in the presence of metal ions such as Cu²⁺ gets accelerated，and Cu²⁺ itself promotes the production of reactive oxygen species (ROS) and increases neurotoxicity. Therefore，it is important to develop dual-function inhibitors that simultaneously chelate copper ions and inhibit Aβ aggregation. In this study，we designed a novel bifunctional decapeptide SSHLVFFARK-NH₂ (SK10) by combining a metal chelating tripeptide (SSH) and an Aβ aggregation inhibitor Ac-LVFFARK-NH₂(LK7). We conducted thioflavin T(ThT) fluorescence and aggregation kinetics experiments and performed atomic force microscopy(AFM)，isothermal titration calorimetry，and MTT cytotoxicity assays to investigate the inhibition and depolymerization of SK10 on the aggregation and cytotoxicity of Aβ in the presence of Cu²⁺. The experimental results show that SK10 can inhibit Aβ₄₀ aggregation in the presence of Cu²⁺(ThT fluorescence decreased by 60%) and the Aβ₄₀ fiber gradually decreased with increase in the SK10 concentration and reduce the cytotoxicity induced by Aβ₄₀ aggregation in the presence of Cu²⁺ such that the cel·
lular activity was restored to ＞90%. Similarly, SK10 inhibited the aggregation of Aβ₄₂ in the presence of Cu²⁺. Because SK10 has a specific affinity for Cu²⁺(K_d＝0.03 μmol/L) and is capable of sequestering Cu²⁺ from Cu²⁺-Aβ₄₀ species，it can inhibit the toxicity of ROS catalyzed by copper ions with respect to cells. Additional studies revealed that the formed Cu²⁺-Aβ₄₀ aggregates can be depolymerized by SK10，whereby the formed Cu²⁺-Aβ₄₀ aggregates disappear and the cell viability is increased to 90%. The above results reflect both the medicinal potential of SK10 and provide ideas for the design and development of bifunctional inhibitors that can chelate metal ions and inhibit Aβ aggregation.\r
\r
Keyword_Chinese:阿尔茨海默症；β-淀粉样蛋白；Cu²⁺螯合剂；金属螯合多肽抑制剂\r

Keywords_English:Alzheimer’s disease；amyloid β-protein；Cu²⁺ chelator；metal chelating peptide inhibitor\r


PDF全文下载地址:http://xbzrb.tju.edu.cn/#/digest?ArticleID=6319