A rapid approach for the detection, quantification, and discovery of novel sulfenic acid or S-nitrosothiol modified proteins using a biotin-switch method.

The recent development of robust methods for the detection of proteins susceptible to S-nitrosylation (RSNO) and sulfenation (RSOH) has provided greater insight into the role of these oxidative modifications in cell signaling. These techniques, which have been termed "biotin-switch" methods, essentially use selective chemical reduction to swap an oxidative modification for a stable easily detectable biotin-tag. This allows for the rapid purification and subsequent detection of modified proteins using mass spectrometry. This chapter provides an overview of these biotin-switch methods, and explores its impact on the field of redox biology, including recent advances as well as limitations associated with this technique. Copyright (c) 2010 Elsevier Inc. All rights reserved.