Design and applications of methods for fluorescence detection of iron in biological systems
Design and applications of methods for fluorescence detection of iron in biological systems
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DOI：
10.1042/bst0300729
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发表时间：
2002-08-01
影响因子：
3.9
通讯作者：
Cabantchik, ZI
中科院分区：
文献类型：
--
作者：
Espósito, BP;Breuer, W;Cabantchik, ZI
荧光金属传感器提供了一种检测生物系统中铁的方法，该方法多功能、经济、灵敏且具有高通量性质。它们依赖于与高荧光探针缀合的相对高亲和力的铁结合载体，这些探针在金属络合后经历猝灭。金属特异性由含有高亲和力（A 型）或相对较低亲和力（B 型）铁结合部分的探针与强特异性铁螯合剂组合使用来确定。由于生物系统的异质性，应具体定义表观金属结合亲和力和络合化学计量。与金属结合核心偶联的荧光素部分可检测亚微摩尔浓度甚至亚微升体积（即细胞）的 Fe。尽管理想的探针还应该针对铁的特定氧化态，但在生理条件下可能难以获得该特性。细胞中不稳定铁的定量依赖于渗透性铁螯合剂恢复被细胞内铁猝灭的探针荧光的能力。现代探针设计旨在 (a) 改进探针对特定细胞区室的靶向性，以及 (b) 创建通过信号增强对金属结合做出反应的探针。
Fluorescence metalosensors provide a means to detect iron in biological systems that is versatile, economical, sensitive and of a high-throughput nature. They rely on relatively high-affinity iron-binding carriers conjugated to highly fluorescent probes that undergo quenching after metal complexation. Metal specificity is determined by probes containing either an iron-binding moiety of high affinity (type A) or of relatively lower affinity (type B) used in combination with a strong specific iron chelator. Due to the heterogeneous nature of biological systems, the apparent metal-binding affinity and complexation stoichiometry ought to be specifically defined. Fluoresceinated moieties coupled to metal-binding cores detect Fe at sub-micromolar concentrations and even submicrolitre volumes (i.e. cells). Although an ideal probe should also be specific for a particular oxidation state of iron, in physiological conditions that property might be difficult to attain. Quantification of labile iron in cells has relied on the ability of permeant iron chelators to restore the fluorescence of probes quenched by intracellular Fe. Modern design of probes alms to (a) improve probe targeting to specific cell compartments and (b) create probes that respond to metal binding by signal enhancement.