高特异性的La^(3+)靶向多肽探针及其在细胞和斑马鱼成像中的应用

Highly Specific La^(3+)-Targeting Peptide Fluorescent Probe and Its Application in Cell and Zebrafish Imaging

研究报道了一种新型多肽探针(TPE-Glu-Glu-Pro-Gly-Glu-Glu-NH2),该多肽探针单独存在时没有荧光,稀土元素镧离子(La^(3+))加入后,与多肽探针特异性结合,限制了四苯乙烯(TPE)分子内的旋转,导致溶液产生强的荧光信号。该探针具有特异性,16种常见金属的存在也几乎不影响其对La^(3+)的靶向检测。我们研究发现,谷氨酸在多肽探针结合La^(3+)的过程中发挥重要作用,减少谷氨酸个数会影响其特异性识别。滴定和Job工作曲线结果表明,该多肽探针与La^(3+)结合比为1∶2,结合常数为1.29×10^(10)(L/mol)^(2)。计算机模拟结果表明,La^(3+)与多肽探针酰胺键的氧和谷氨酸羧基中羟基的氧结合。该探针可以高灵敏检测水溶液和唾液中的La^(3+),检测限分别为0.12μmol/L和0.32μmol/L。该高灵敏、高特异性多肽探针具有良好的生物相容性,可以用于细胞和斑马鱼中La^(3+)靶向成像,在环境和医学样品检测中有巨大的应用潜力。

As an important rare earth element,lanthanum ion is widely used in industry and medicine,but its excessive residue can cause serious environmental and health problems.Therefore,the development of efficient detection methods for lanthanum ions is of great significance for environmental protection and human health.We report for the first time a novel peptide probe(TPE-Glu-Glu-Pro-Gly-Glu-Glu-NH2),which has no fluorescence when it exists alone.After La^(3+)is added,the peptide probe can specifically detect La^(3+)due to the restriction of intramolecular rotation of TPE,which causes a strong fluorescent signal in the solution.The probe is specific,and the presence of 16 common metals does almost not affect its targeted detection of La^(3+).Our study found that glutamate plays an important role in binding peptide probes to La^(3+),and reducing the number of glutamates will affect its specific recognition.The results of titration and Job curve show that the binding ratio of the peptide probe to La^(3+)was 1∶2,and the binding constant was 1.29×10^(10)(L/mol)^(2).The computer simulation results show that La^(3+)binds to the oxygen of the amide bond of the peptide probe and the oxygen of the hydroxyl group of the carboxyl group of glutamic acid.The probe can detect La^(3+)in aqueous solution and saliva with high sensitivity with detection limits of 0.12 and 0.32μmol/L,respectively.This highly sensitive and highly specific peptide probe has good biocompatibility,can be used for La^(3+)targeted imaging in cells and zebrafish,and has great application potential in the detection of environmental and medical samples.