摘要
半胱氨酸蛋白酶-3(caspase-3)是细胞凋亡过程中的主要效应子之一,在多种疾病的检测中扮演重要角色,对其在低浓度下的检测是早期发现肿瘤细胞的有效手段.参考近期发现的caspase-3剪切诱导发生的高效缩合反应,设计了化合物Ac-Asp-Glu-Val-Asp-Cys(StBu)-Lys(FITC)-CBT(1),通过TCEP(三(2-羧乙基)膦)还原以及在细胞凋亡过程中高表达的caspase-3的特异性识别剪切后发生缩合反应,其二聚体产物亲脂亲水性发生变化,可以自组装形成纳米粒子,并由于聚集荧光淬灭效应导致荧光强度较反应前大幅降低,从而实现caspase-3的检测.反应生成的纳米粒子通过高效液相色谱、动态光散射仪以及透射电镜等手段进行表征,表明化合物1可以在低物质的量浓度下由几个单位的蛋白酶成功剪切缩合并自组装成纳米荧光探针,其荧光强度降低幅度与酶的含量在一定范围内成线性关系,可用于caspase-3酶在低浓度下的检测.
Caspase-3is a very important protease in cell apoptosis and plays a crucial role in many diseases.A new probe Ac-Asp-Glu-Val-Asp-Cys(StBu)-Lys(FITC)-CBT(1)was reported,which can be reduced by TCEP and cleaved by caspase-3to yield the amphiphilic dimer(1-D).1-Dcan quickly self-assemble into nanoparticles to induce a clear fluorescence quenching effect because of the aggregation-caused quench.The nanoparticles were characterized by means of dynamic light scattering(DLS),transmission electron microscope(TEM),and high performance liquid chromatography(HPLC).As a result,the fluorescence intensity has a linear correlation with the concentration of caspase-3,which could be applied to sensing caspase-3activity in vivo in the future.
基金
国家自然科学基金(21175122)资助
