Cysteine sulfinic acid decarboxylase (CSAD)

Cysteine sulfinic acid decarboxylase (CSAD) is a pyridoxal 5'-phosphate-dependent enzyme that catalyzes the decarboxylation of cysteine sulfinic acid to hypotaurine, the critical and rate-limiting step in de novo taurine biosynthesis. Taurine is essential for multiple physiological processes, including osmoregulation, bile acid conjugation, antioxidative protection, and development of the central nervous system, heart, and liver. CSAD is highly regulated in tissues with metabolic and developmental demands. Loss of CSAD activity in animal models causes diminished taurine and hypotaurine levels, leading to compromised antioxidant defenses and altered bile acid metabolism. Biochemically, CSAD is closely related to other PLP-dependent decarboxylases and belongs to the aspartate aminotransferase fold type I superfamily. While no drugs currently target CSAD clinically, its structure and mechanism have been studied for potential inhibitor development[1][2][4][5][6].

Other names

Cysteine sulfinic acid decarboxylaseCSADCysteine-sulfinate decarboxylaseSulfinoalanine decarboxylaseAspartate 1-decarboxylaseP-selectin cytoplasmic tail-associated protein (PCAP)CSDcysteine sulfinic acid decarboxylase-related protein

Enzyme inhibition (theoretical, for compounds designed to inhibit CSAD activity and modulate taurine levels; not in clinical use)