Detection of protein S-sulfhydration by a tag-switch technique

Abstract

Protein S-sulfhydration (forming -S-SH adducts from cysteine residues) is a newly defined oxidative posttranslational modification and plays an important role in H2S-mediated signaling pathways. In this study we report the first selective, "tag-switch" method which can directly label protein S-sulfhydrated residues by forming stable thioether conjugates. Furthermore we demonstrate that H2S alone cannot lead to S-sulfhydration and that the two possible physiological mechanisms include reaction with protein sulfenic acids (P-SOH) or the involvement of metal centers which would facilitate the oxidation of H2S to HS.. Selective detection: The first selective tag-switch method can be used to directly label protein persulfide units (sites of S-sulfhydration) in the form of stable thioether conjugates. It is thought that H2S alone cannot lead to S-sulfhydration and that the two possible physiological mechanisms include reaction with protein sulfenic acids (P-SOH) and the involvement of metal centers, which would facilitate the oxidation of H2S to HS.. © 2014 WILEY-VCH Verlag GmbH.