Description

3-Sulfinoalanine (https://pubchem.ncbi.nlm.nih.gov/compound/3-Sulfinoalanine) or cysteinesulfinic acid (https://pubchem.ncbi.nlm.nih.gov/compound/cysteinesulfinic%20acid) is a N-methyl-D-aspartate (https://pubchem.ncbi.nlm.nih.gov/compound/N-methyl-D-aspartate) agonist. It is a product of cysteine (https://pubchem.ncbi.nlm.nih.gov/compound/cysteine) dioxygenase or CDO [EC 1. 13. 11. 20]. In humans cysteine (https://pubchem.ncbi.nlm.nih.gov/compound/cysteine) catabolism is tightly regulated via regulation of cysteine (https://pubchem.ncbi.nlm.nih.gov/compound/cysteine) dioxygenase (CDO) levels in the liver, with the turnover of CDO protein being dramatically decreased when intracellular cysteine (https://pubchem.ncbi.nlm.nih.gov/compound/cysteine) levels increase. This occurs in response to changes in the intracellular cysteine (https://pubchem.ncbi.nlm.nih.gov/compound/cysteine) concentration via changes in the rate of CDO ubiquitination and degradation. Expressed at high levels in the liver with lower levels in the kidney, brain, and lung, cysteine (https://pubchem.ncbi.nlm.nih.gov/compound/cysteine) dioxygenase catalyzes the addition of molecular oxygen (https://pubchem.ncbi.nlm.nih.gov/compound/molecular%20oxygen) to the sulfhydryl group of cysteine (https://pubchem.ncbi.nlm.nih.gov/compound/cysteine), yielding cysteinesulfinic acid (https://pubchem.ncbi.nlm.nih.gov/compound/cysteinesulfinic%20acid). The oxidative catabolism of cysteine (https://pubchem.ncbi.nlm.nih.gov/compound/cysteine) to cysteinesulfinate by CDO represents an irreversible loss of cysteine (https://pubchem.ncbi.nlm.nih.gov/compound/cysteine) from the free amino acid pool. Once generated, cysteinesulfinate is shuttled into several pathways including hypotaurine (https://pubchem.ncbi.nlm.nih.gov/compound/hypotaurine)/taurine (https://pubchem.ncbi.nlm.nih.gov/compound/taurine) synthesis, sulfite (https://pubchem.ncbi.nlm.nih.gov/compound/sulfite)/sulfate (https://pubchem.ncbi.nlm.nih.gov/compound/sulfate) production, and the generation of pyruvate (https://pubchem.ncbi.nlm.nih.gov/compound/pyruvate).