N-Dansyl-S-nitrosohomocysteine a fluorescent probe for intracellular thiols and S-nitrosothiols

Document Type

Article

Publication Date

1999

Publication Title

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology

Volume

1430

Issue

1

First Page

149

Last Page

154

Abstract

The fluorescence emission spectrum of N-dansyl-S-nitrosohomocysteine was enhanced ∼8-fold upon removal of the NO group either by photolysis or by transnitrosation with free thiols like glutathione. The fluorescence enhancement was reversible in that it could be quenched in the presence of excess S-nitrosoglutathione. Attempts were then made to utilize N-dansyl-S-nitrosohomocysteine as an intracellular probe of thiols/S-nitrosothiols. Fluorescence microscopy of fibroblasts in culture indicated that intracellular N-dansyl-S-nitrosohomocysteine levels reached a maximum within 5 min. N-Dansyl-S-nitrosohomocysteine fluorescence was directly proportional to intracellular GSH levels, directly determined with HPLC. N-Dansyl-S-nitrosohomocysteine preloaded cells were also sensitive to S-nitrosoglutathione uptake as the intracellular fluorescence decreased as a function of time upon exposure to extracellular S-nitrosoglutathione.

DOI

10.1016/S0167-4838(98)00286-6

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