Metal-specific fluorescence probes are of increasing importance in understanding the neurobiology and general cell biology of zinc. Several quinoline-based compounds such as TSQ and zinquin have been employed to detect zinc in fluorescence microscopy experiments in vivo; however, the aqueous solution chemistry remains equivocal. In some cases, this family of probes is said to reveal labile pools of Zn(II) inside the cell, yet in other cases, these probes are suggested to remove Zn(II) from tightly bound sites in proteins. Since the binding modes, coordination numbers, and thermodynamics of zinc−zinquin interactions in aqueous solution have not been established, these proposals are difficult to distinguish. Here we show that, under physiological conditions, the various forms of zinquin bind Zn(II) with a high degree of cooperativity forming 2:1 complexes. Potentiometric, UV−visible, and fluorescence methods all yield an overall binding constant of log K = 13.5 under physiological conditions. To put this nu...

Aqueous Coordination Chemistry of Quinoline-Based Fluorescence Probes for the Biological Chemistry of Zinc

Three coordination in metal complexes

Five-coordination in iron(II); cobalt(II) and nickel(II) complexes

The Jaffé reaction. Identification of the coloured species.

The role of pH in the melanin biosynthesis pathway.

Graphical methods for determining the number of species in solution from spectrophotometric data

Preparation and Properties of Americium(VI) in Aqueous Carbonate Solutions

The Kinetics of the Disproportionation of Americium(V)

Study of the Ni(CN)42- and Ni(CN)53- Equilibrium by Electronic and Vibrational Absorption Spectra; Effect of Fluoride Ion

Mixed-ligand complexes in mercury(II)-cyanide-iodide solutions: a Raman and ultraviolet study

James S. Coleman

Papers

Graphical methods for determining the number of species in solution from spectrophotometric data

Preparation and Properties of Americium(VI) in Aqueous Carbonate Solutions

The Kinetics of the Disproportionation of Americium(V)

Study of the Ni(CN)42- and Ni(CN)53- Equilibrium by Electronic and Vibrational Absorption Spectra; Effect of Fluoride Ion

Mixed-ligand complexes in mercury(II)-cyanide-iodide solutions: a Raman and ultraviolet study