What is the role of cystathionine beta-synthase?

The cystathionine ß-synthase (CBS) is a critical enzyme in the transsulfuration pathway and is responsible for the synthesis of cystathionine from serine and homocysteine. Cystathionine is a precursor to amino acid cysteine. CBS is also responsible for generation of hydrogen sulfide (H2S) from cysteine.

What is the CBS enzyme?

The CBS gene provides instructions for making an enzyme called cystathionine beta-synthase. This enzyme acts in a chemical pathway and is responsible for using vitamin B6 to convert building block of proteins (amino acid) called homocysteine and serine to a molecule called cytathionine.

What enzyme is deficient in homocystinuria?

In most cases, homocystinuria is caused by reduced activity of an enzyme known as cystathionine beta-synthase and this results in CBS deficiency.

What is a CBS mutation?

This form of homocystinuria is caused by a genetic mutation in the CBS gene , which leads to low levels or absence of an enzyme called cystathionine beta-synthase (CBS). When CBS is absent or not working right, homocysteine and other toxic chemicals build up in the blood and urine.

Where is the CBS gene located?

Cystathionine beta synthase

What causes cysteine deficiency?

Cysteine deficiencies identified by inherited metabolic disorders or reduced levels in body fluid have been associated with: 1) impaired antioxidant defenses; 2) decreased ability to metabolize drugs or toxic compounds; 3) depressed immune functions; 4) some psycoses; and 5) homocystinemia.

Why does blood clot occur in homocystinuria?

Rapidly accumulating evidence links elevated homocysteine levels to thrombosis via several mechanisms such as increased tissue factor expression, attenuated anticoagulant processes, enhanced platelet reactivity, increased thrombin generation, augmented factor V activity, impaired fibrinolytic potential, and vascular …