ABSTRACT
Zinc ion (Zn2+) is the second most abundant transition metal in living organisms after iron. In cells, Zn2+ serves as an important cofactor of numerous proteins to maintain their structures or support their enzymatic activities. It has been estimated that roughly 2800 human proteins potentially bind Zn2+ in vivo, corresponding to about 10% of the human proteome (Andreini et al. 2006). A well-known example is the zinc nger transcription factors, a large family of Zn2+-binding proteins involved in the regulation of gene expression (Klug 2010). Because of the essential roles Zn2+ plays in diverse biochemical, biological, and physiological processes, as well as its involvement in a number
11.1 Why Imaging Zn2+? 291 11.2 Fluorescent Sensors for Imaging Zn2+ Dynamics in Biological Fluids 293
11.2.1 Design Principles-Zinc Coordination Chemistry and Commonly Used Ligands 293
11.2.2 Small Synthetic Zn2+ Indicators 294 11.2.3 Genetically Encoded Zn2+ Indicators 299
11.3 Applications of Fluorescent Zn2+ Sensors 301 11.3.1 Measuring Intracellular Zn2+ 301 11.3.2 Measuring Zn2+ in the Extracellular Fluid of Physiological
Preparations 304 11.3.3 Imaging Zn2+ Secretion 304
11.4 Outlook 308 References 310
of human diseases (Rungby 2010; Fukada et al. 2011; Sensi et al. 2011), increasing interest and eort have been devoted to study the regulation and function of Zn2+ homeostasis in dierent biological systems.
