Fluorogenic probes using 4-substituted-2-nitrobenzenesulfonyl derivatives as caging groups for the analysis of human glutathione transferase catalyzed reactions

Ralf Mogenstern,Yasuhiko Yoshida,Aya Shibata,Yukiko Nakano,Hiroshi Abe,Jie Zhang,Mika Araki,Bengt Mannervik,Satoshi Shuto,Mika Ito,Yoshihiro Ito

doi:10.1039/c3an01339a

Abstract

We have synthesized a series of 4-substituted-2-nitrobenzene-sulfonyl compounds for caged fluorogenic probes and conducted a Hammett plot analysis using the steady-state kinetic parameters. The results revealed that the glutathione transferase (GST) alpha catalyzed reaction was dependent on the σ value in the same way as the non-enzymatic reaction, whereas the dependence of the σ value of the GST mu and pi was not as pronounced as that of GST alpha.

Highlights

Fluorogenic probes using 4-substituted-2nitrobenzenesulfonyl derivatives as caging groups for the analysis of human glutathione transferase catalyzed reactions†
The results revealed that the glutathione transferase (GST) alpha catalyzed reaction was dependent on the s value in the same way as the non-enzymatic reaction, whereas the dependence of the s value of the GST mu and pi was not as pronounced as that of GST alpha
The effects of electron-withdrawing groups on SNAr reactions catalyzed by rat GSTs have been examined using several 2- or 4-substituted CDNB analogs, and a linear correlation was reported between the reactions catalyzed by the rat GSTs and the Hammett substituent constant.[21,22,23,24,25]

Summary

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We have examined the catalytic capacity of the main human cytosolic GSTs (i.e., alpha, mu and pi) towards the GSH conjugation reactions of a series of 4-substituted-2-nitrobenzenesulfonyl group caged mono-acetyl rhodamine (AcRh) compounds. The uorescence signals increased with time for all of the probes following the deprotection of the caged group to the amino group of the AcRh. In the case of DNs-AcRh, the reaction reached 80% conversion a er 6 min and reached the saturation phase. Hammett plots were constructed from these kinetic parameters to investigate the relationship between the GST catalyzed reaction and the nature of the electron-withdrawing substituents.

Without GST

Conclusions