High impact information on Mtr

• In the control system, 5-methyltetrahydrofolate homocysteine methyltransferase, betaine homocysteine methyltransferase, and cystathionine beta-synthase accounted for 27, 27, and 46%, respectively, of the homocysteine consumed [1].
• This gas decreases activity of the enzyme 5-methyltetrahydrofolate homocysteine methyltransferase (methionine synthetase) and alters the level and distribution of folic acid derivatives in embryonic tissue [2].
• Prior exposure of rats to a mixture of nitrous oxide/oxygen (80/20) for 20 to 24 hours and feeding rats a diet deficient in vitamin B-12 and methionine for 23 weeks resulted in a 86 to 90% decrease in the activity of the vitamin B-12 dependent enzyme, 5-methyltetrahydrofolate-homocysteine methyltransferase (EC 4.2.99.10) [3].
• The presence of 5,10-methylenetetrahydrofolate reductase and 5-methyltetrahydrofolate-homocysteine methyltransferase were confirmed in rat bone marrow and they were inhibited by S-adenosylmethionine and methionine, respectively, in a similar fashion to that found with the liver enzymes [4].
• The important features of the enzymes involved in methionine synthesis in sheep were found to be the low activity of betaine-homocysteine methyltransferase and the high activity of 5-methyltetrahydrofolate-homocysteine methyltransferase [5].

References