Metabolite in cysteine and methionine metabolism, important intermediate in the mercaptopyruvate pathway, in which cysteine or aspartate transaminase catalyzes the transamination from cysteine to 3-mercaptopyruvate and then 3-mercaptopyruvate sulfurtransferase catalyzes the transsulfuration from 3-mercaptopyruvate to pyruvate, a process contributing to maintain the cellular redox status. It is a substrate for L-lactate dehydrogenase A chain, 3-mercaptopyruvate sulfurtransferase, Aspartate aminotransferase (mitochondrial), L-lactate dehydrogenase C chain, L-lactate dehydrogenase A-like 6A, Aspartate aminotransferase (cytoplasmic), L-lactate dehydrogenase B chain and L-lactate dehydrogenase A-like 6B.