Work

Fluorescent indicators for cytosolic sodium

Year: 1989

Type: article

Abstract: Fluorescent indicators sensitive to cytosolic concentrations of free Na+ have been synthesized and characterized. They consist of a crown ether, 1,7-diaza-4,10,13-trioxacyclopentadecane, linked via its nitrogens to fluorophores bearing additional liganding centers. In the currently preferred dye, SBFI (short for sodium-binding benzofuran isophthalate), the fluorophores are benzofurans linked to isophthalate groups. Selectivities for Na+ over K+ of about 20 are observed, resulting in effective dissociation constants for Na+ of about 20 mM against a background of 120 mM K+. Increasing [Na+] increases the ratio of excitation efficiency at 330-345 nm to that at 370-390 nm with emission collected at 450-550 nm, so that ratio fluorometry and imaging can be performed with the same wavelengths as used with the well known Ca2+ indicator fura-2. If the macrocyclic ring is increased in size to a 1,10-diaza-4,7,13,16-tetraoxacyclooctadecane, the chelators become selective for K+ over Na+.

Source: Journal of Biological Chemistry

DOI: 10.1016/s0021-9258(19)47321-3

Authors: A Minta, R Y Tsien

Institutions: University of California, Berkeley, University of California San Diego

Language: English

Topic: Molecular Sensors and Ion Detection

Subfield: Spectroscopy

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funders: National Eye Institute, National Institute of General Medical Sciences