A Pentapeptide with Tyrosine Moiety as Fluorescent Chemosensor for Selective Nanomolar-Level Detection of Copper(II) Ions
A Pentapeptide with Tyrosine Moiety as Fluorescent Chemosensor for Selective Nanomolar-Level Detection of Copper(II) Ions
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DOI：
10.3390/ijms21030743
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发表时间：
2020-02-01
影响因子：
5.6
通讯作者：
Makowska, Joanna
中科院分区：
文献类型：
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作者：
Zamojc, Krzysztof;Kamrowski, Dominik;Makowska, Joanna
在这里，我们主要研究了使用紫外和荧光（稳态和时间分辨）光谱法：五肽与酪氨酸残基的相互作用（EYHHQ、EHYHQ、EHHQY和KYHHE）和各种金属离子（Cu 2+、Mn 2+、Co2+、Ni 2+、Zn 2+、Cr 3+、Cd 2+、Ag+、Pb 2+、Sr 2+、Ba 2+、Ca 2+、Mg 2+、Al 3+、Fe 2+和Ga 3+），以建立肽序列中酪氨酸残基的位置与金属离子结合性质之间的关系。在所研究的肽中，EHYHQ被评价为用于开发用于检测铜（II）离子的化学传感器的有效和选择性配体。虽然在Cu 2+阳离子存在下观察到该肽的显著荧光发射猝灭，但以相同和相当高的浓度使用的其他金属阳离子引起荧光发射光谱的可忽略的变化，表明EHYHQ对Cu 2+离子的高选择性。在最佳条件下，荧光强度与Cu 2+浓度成反比。使用EHYHQ的Cu 2+离子的检测限确定为26.6 nM水平。研究的肽与Cu 2+离子的复合物的结合化学计量进行了评价，荧光（如通过质谱法确认的EHYHQ的情况下），并发现为1：2（Cu 2 +-肽）的所有研究系统。并测定了这些配合物的稳定常数K值。证实了该铜离子传感器的可逆性，确定了该传感器作用的pH范围，并将其分析性能与最近报道的其他一些荧光传感器进行了比较。根据核磁共振谱研究，提出了EHYHQ与Cu ~（2+）的相互作用机理。
Herein, we have investigated principally with the use of UV and fluorescence (steady-state and time-resolved) spectroscopy the interactions between selected pentapeptides with tyrosine residue (EYHHQ, EHYHQ, EHHQY, and KYHHE) and various metal ions (Cu2+, Mn2+, Co2+, Ni2+, Zn2+, Cr3+, Cd2+, Ag+, Pb2+, Sr2+, Ba2+, Ca2+, Mg2+, Al3+, Fe2+, and Ga3+) in order to establish the relationship between the position of a tyrosine residue in the peptide sequence and the metal ion-binding properties. Among the peptides studied, EHYHQ was evaluated as an efficient and selective ligand for developing a chemosensor for the detection of copper(II) ions. While significant fluorescence emission quenching was observed for that peptide in the presence of Cu2+ cations, other metal cations used at the same and at considerably higher concentrations caused a negligible change of the fluorescence emission spectrum, indicating a high selectivity of EHYHQ for Cu2+ ions. Under optimum conditions, fluorescence intensity was inversely proportional to the concentration of Cu2+ ions. The limit of detection of Cu2+ ions with the use of EHYHQ was determined at the level of 26.6 nM. The binding stoichiometry of the complexes of the studied peptides with Cu2+ ions was evaluated spectrophotometrically and fluorimetrically (as in the case of EHYHQ confirmed by mass spectrometry) and found to be 1:2 (Cu2+-peptide) for all the investigated systems. Furthermore, the stability constant (K) values of these complexes were determined. The reversibility of the proposed Cu2+ ions sensor was confirmed, the pH range where the sensor acts was determined, while its analytical performance was compared with some other reported recently fluorescent sensors. The mechanism of the interactions between EHYHQ and Cu2+ was proposed on the basis of NMR spectroscopy investigations.