PROTEIN-SULFENIC
ACIDS
A growing area of study in cellular physiology is the role of redox regulation
of various cellular processes. While sulfenic acids are usually quite
reactive and unstable, several proteins have been found with unusually stable
Cysteine-sulfenicacid (Cys-SOH) groups. Cysteine-sulfenic acids have
been found to play integral roles in signal transduction, regulation, and
catalysis in diverse proteins including transcription factors Fos and Jun,
E2, nitrile hydratase, protein tyrosine phosphatases, and peroxiredoxins.
Sulfenic acid possesses unique redox characteristics which allow it
to fulfill a regulatory role. The molecular basis of redox sensitivity
in proteins is far from being understood, but Cys-SOH seems to play a key
role which current laboratory efforts are attempting to reveal.