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.