CTH Human

Cystathionase, also known as cystathionine gamma-lyase (CTH), is an enzyme that plays a crucial role in the trans-sulfuration pathway. This pathway is essential for the conversion of methionine to cysteine, which is a vital amino acid for various biological functions, including the synthesis of glutathione in the liver .

Human recombinant cystathionase is typically produced in Escherichia coli (E. coli) and is a single, non-glycosylated polypeptide chain containing 425 amino acids. The molecular mass of this enzyme is approximately 46.7 kDa . The recombinant form is often fused to a His-tag at the N-terminus to facilitate purification through chromatographic techniques .

The enzyme is usually formulated in a buffer containing 20mM Tris-HCl (pH 8.0), 2mM DTT, 10% glycerol, and 100mM NaCl. It is recommended to store the enzyme at 4°C for short-term use (2-4 weeks) or at -20°C for long-term storage. To prevent degradation, it is advisable to avoid multiple freeze-thaw cycles .

Cystathionase catalyzes the final step in the trans-sulfuration pathway, breaking down cystathionine into cysteine and alpha-ketobutyrate. This reaction is crucial for maintaining adequate levels of cysteine, which is necessary for the synthesis of glutathione, a major antioxidant in the liver .

Mutations in the CTH gene can lead to a condition known as cystathioninuria, characterized by the accumulation of cystathionine in the urine. This condition can have various clinical manifestations, including developmental delays and intellectual disabilities .

Recombinant human cystathionase is widely used in research to study the trans-sulfuration pathway and its role in various physiological and pathological conditions. It is also used in the development of therapeutic strategies for diseases related to oxidative stress and sulfur amino acid metabolism .