methionine synthase การใช้

• Methionine synthase reductase regenerates a functional methionine synthase via reductive methylation.
• Methionine synthase reductase regenerates a functional methionine synthase via reductive methylation.
• The consequence of reduced methionine synthase activity is megaloblastic anemia.
• Methionine synthase eventually becomes inactive due to the oxidation of its cofactor.
• Its synthesis is catalyzed by the enzyme methionine synthase.
• An enzyme mediating methylation, methionine synthase, uses an active form of vitamin B 12 to complete its chemical function.
• In the other enzymatic reaction, methylcobalamin supports the methionine synthase reaction, which is essential for normal metabolism of folate.
• A separate protein, Methionine Synthase Reductase, catalyzes the regeneration of Co ( I ) and the restoration of enzymatic activity.
• Nitrous oxide also inhibits methionine synthase and slows the conversion of homocysteine to methionine, increases homocysteine concentration and decreases methionine concentration.
• The other enzymes containing homologs of POR are nitric oxide synthase ( ), NADPH : sulfite reductase ( ), and methionine synthase reductase ( ).
• The major pathway involves the enzyme methionine synthase, which requires vitamin B 12 as a cofactor, and also depends indirectly on folate and other B vitamins.
• The defect involves these women's inability to make enough of an enzyme called methionine synthase when they ingest usual amounts of folic acid and B-12.
• Levomefolic acid is generated by MTHFR from 5, 10-methylenetetrahydrofolate ( MTHF ) and used to recycle homocysteine back to methionine by methionine synthase ( MS ).
• Patients of the " cblE " complementation group of disorders of folate / cobalamin metabolism which results in homocystinuria are defective in reductive activation of methionine synthase.
• In plants and microorganisms, methionine synthase serves a dual purpose of both perpetuating the SAM cycle and catalyzing the final synthetic step in the de novo synthesis of Met.
• The disorder may be distinguished from the re-methylation defects ( e . g ., MTHFR, methionine synthase deficiency and the cobalamin defects ) in lieu of the elevated methionine concentration.
• BHMT makes up to 1.5 % of all the soluble protein of the liver, and recent evidence suggests that it may have a greater influence on methionine and homocysteine homeostasis than methionine synthase.
• While the reaction is exactly the same for both processes, the overall function is distinct from methionine synthase in humans because Met is an essential amino acid that is not synthesized de novo in the body.
• It inhibits agarase DagA expression by direct base pairing to the dagA coding region, and it represses translation of methionine synthase " metE " ( SCO0985 ) at the 5 end of its open reading frame.
• Because the oxidation of cob-Co ( I ) inevitably shuts down cob-dependent methionine synthase activity, defects or deficiencies in methionine synthase reductase have been implicated in some of the disease associations for methionine synthase deficiency discussed below.