Redox Regulation of Cysteine-Dependent Enzymes in Neurodegeneration

Table 1

Examples of cysteine-dependent enzymes that use cysteine within their catalytic site within the various domains as delineated by the enzyme commission categories.

Class 1	Class 2	Class 3	Class 4	Class 5	Class 6
Oxidoreductases	Transferases	Hydrolases	Lyases	Isomerases	Ligases
Protein-disulfide reductase	Mercaptopyruvate sulfurtransferase	PTEN	MerB^*	Protein disulfide isomerase	Parkin
Peroxiredoxin	Akt	Ubiquitinyl hydrolase 1	LuxS^*	GluRS^*
Glyceraldehyde-3-phosphate dehydrogenase	Janus kinase 2	Histone deacetylase
SOD1	Sulfurtransferase	PTP1B
ALDH1L1	Epidermal growth factor receptor
Tyrosine hydroxylase

^∗For some enzymes above, data suggests that they are oxidized and that the cysteine is essential for activity but may or may not be considered part of the catalytic site in all species.
Note: Other enzymes are not listed here although they depend upon cysteine for activity; often such cysteines are linked to a structural requirement such as a disulfide bond rather than as part of a catalytic domain.