cystathionine การใช้

• Cystathionine beta synthase ( CBS ) is involved in oocyte development.
• L-Serine dehydratase condenses homocysteine with serine to form cystathionine.
• A final transaldimination reaction releases the final product, cystathionine.
• Cystathionine, an intermediary product of this biochemical pathway, is secreted in urine.
• Cystathionine beta synthase catalyzes the upper reaction and cystathionine gamma-lyase catalyzes the lower reaction.
• Cystathionine beta synthase catalyzes the upper reaction and cystathionine gamma-lyase catalyzes the lower reaction.
• The amino group on cystathionine is deprotonated and undergoes a nucleophilic attack of the internal aldimine.
• Cystathionine gamma lyase also shows gamma-synthase activity depending on the concentrations of reactants present.
• Transsulfuration, catalyzed by CBS, converts homocysteine to cystathionine, which cystathione gamma lyase converts to cysteine.
• It is then cleaved into cysteine and ?-ketobutyrate by cystathionine gamma-lyase ( lower reaction ).
• Nucleophilic attack by the thiolate of homocysteine on the aminoacrylate and reprotonation at C? generate the external aldimine of cystathionine.
• Biosynthetically, cystathionine is generated from homocysteine and serine by cystathionine beta synthase ( upper reaction in the diagram below ).
• Biosynthetically, cystathionine is generated from homocysteine and serine by cystathionine beta synthase ( upper reaction in the diagram below ).
• Cystathionine ?-synthase ( CBS ) deficiency is a serious disorder of transsulfuration which is managed with methionine restricted dieting.
• Cystathionase uses pyridoxal phosphate to facilitate the cleavage of the sulfur-gamma carbon bond of cystathionine, resulting in the release of cysteine.
• One of the alternate reactions involving CBS is the condensation of cysteine with homocysteine to form cystathionine and hydrogen sulfide ( H 2 S ).
• It was first identified as a conserved sequence region in 1997 and named after cystathionine beta synthase, one of the proteins it is found in.
• These results agree with the proposed ping-pong mechanism in which serine binding and release of water are followed by homocysteine binding and release of cystathionine.
• _Homocystinuria, occurring in one baby in 275, 000, involves a deficiency of an enzyme that converts homocysteine into cystathionine, needed for normal brain development.
• Several novel inhibits enzymes involved in the metabolism of the amino acids methionine and cystathionine in the liver; it was also shown to have mild inhibitory effects on the glycogenolysis metabolic pathway in rat liver cells.