靶向检测Cu^(2+)和S^(2-)的多肽探针及其在细胞和斑马鱼成像中的应用

Peptide probe for the specific detection of Cu^(2+)and S^(2-)and its application in cells and zebrafish imaging

设计了一种新型多肽探针L(Dansyl-Gly-Ser-Ser-Gly),该多肽探针L单独存在时有强的荧光信号,Cu^(2+)的顺磁性淬灭传感机制可导致多肽探针L的荧光淬灭。因此探针L可以靶向检测Cu^(2+)而不受其他常见金属离子的干扰。滴定和Job工作曲线结果表明,L-Cu检测平台以摩尔比1∶1的方式结合,结合常数为8.60×10^(4)L/mol。计算机模拟结果表明,Cu^(2+)与多肽探针L中的2个丝氨酸上的氮原子结合。S^(2-)的加入使L-Cu检测平台中的多肽探针L游离出来,多肽探针L的荧光恢复。多肽探针L能够实现对Cu^(2+)和S^(2-)的靶向检测,并以“On-Off-On”模式响应,检出限分别为114 nmol/L和357 nmol/L。多肽探针L已成功用于L929细胞和斑马鱼中Cu^(2+)和S^(2-)的荧光成像,为人体内靶向检测Cu2+和S2-提供了一种新的机遇。

A novel peptide probe L(Dansyl-Gly-Ser-Ser-Gly)was designed,which had strong fluorescence when it existed alone.The paramagnetic property of Cu^(2+)could lead to its fluorescence quenching,so the peptide probe L could specifically detect Cu^(2+)without the interferences of other common metal ions.The results of titration and Job curve showed the formation of the L-Cu platform at 1∶1 stoichiometry,and the binding constant was 8.60×10^(4) L/mol.The computer simulation results showed that the binding of Cu^(2+)and peptide probe L was mediated by two coordination sites(N atom of two Ser).While the addition of S^(2-)released the peptide probe L from the L-Cu platform and recovered its fluorescence.The results showed that the peptide probe L could achieve specific detection of Cu^(2+)and S^(2-)via an"Off-On-Off"mode with the detection limits of 114 nmol/L and 357 nmol/L,respectively.The peptide probe L was successfully used for the fluorescence imaging of Cu^(2+)and S^(2-)in L929 cells and zebrafish.It provides a novel opportunity for specific detection of Cu^(2+)and S^(2-)in vivo.