In enzymology, a cysteine transaminase is an enzyme that catalyzes the chemical reaction L-cysteine + 2-oxoglutarate ⇌ {\displaystyle \rightleftharpoons } mercaptopyruvate + L-glutamateThus, the two substrates of this enzyme are L-cysteine and 2-oxoglutarate, whereas its two products are mercaptopyruvate and L-glutamate. Wikipedia