3-Mercaptopyruvate sulfurtransferase (3MST) is a sulfur metabolism enzyme involved in the synthesis of hydrogen sulfide (H₂S), an important signaling molecule. 3MST consists of multiple functional domains and is mainly located in the cytoplasm and mitochondria. The expression of this enzyme varies in different tissues and cells, participating in the regulation of vascular tone, neurotransmission, and antioxidant stress response. 3MST catalyzes the formation of H₂S from 3-mercaptopyruvate and L-cysteine, affecting cellular signaling and metabolism. Mutations or dysregulation in the gene encoding 3MST are associated with various diseases, including cardiovascular diseases, neurodegenerative diseases, and inflammation.