BCN-E-BCN is a strained cycloalkyne probe for detecting proteins that have been sulfenylated, the first intermediate step in protein oxidation. BCN-E-BCN is selective for the sulfenic acid form of thiol oxidation and does not label free thiol, sulfinic, or sulfonic forms of proteins. The BCN-E-BCN protein conjugate can be detected using copper-free click chemistry to attach azide-bearing biotin or fluorescent tags. It is highly reactive and faster-acting than other sulfenic acid probes.
