Table 1.

Redox cysteine oxidation states.

Name	Formulae	Oxidation State
Cysteine	R–SH	−II
Disulfide bridge	R–S–S–R	−I
Glutathionylation	R–S–S–G	−I
Sulfenic acid	R–SOH	0
Sulfinic acid	R–SO2H	+II
Sulfonic acid	R–SO3H	+IV