Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.5.7.1 (methylenetetrahydrofolate reductase)
 2,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The specific activities of four folate enzymes have been measured in livers from preterm infants (Group 1), full-term infants (Group 2), and from control subjects (Group 3). The four enzymes studied were methylene tetrahydrofolate reductase (EC 1.1.1.68), methionine synthetase (EC 2.1.1.13), methylenetetrahydrofolate dehydrogenase (EC 1.5.1.5), and glutamate formiminotransferase (EC 2.1.2.5). The specific activities for methylenetetrahydrofolate reductase were 6.62 +/- 0.51, 4.42 +/- 0.31, and 2.60 +/- 0.40 (nmoles formaldehyde/mg protein/h, mean +/- S.E.) for groups 1, 2 and 3, respectively. The specific activities for the three groups for methionine synthetase were 0.99 +/0 0.11, 0.64 +/- 0.06, and 0.42 +/- 0.05 (nmoles methionine/mg protein/h), mean +/- S.E.). The specific activities for the three groups for glutamine formiminotransferase were 84.1 +/-10.7, 108.6 +/-14.6, and 104.3 +/- 17.8 (nmoles methenyltetrahydrofolate/mg protein/min, mean +/- S.E.). The specific activities for the three groups for methylenetetrahydrofolate dehydrogenase were 0.16 +/- 0.03, 0.39 +/- 0.07, and 0.92 +/- 0.16 (nmoles methenyltetrahydrofolate/mg protein/min, mean +/- S.E.). During development, the specific activities of methylenetetrahydrofolate reductase and methionine synthetase decreased whereas the specific activity of methylenetetrahydrofolate dehydrogenase increased and that of glutamate formiminotransferase remained constant. In addition, the activities of methylenetetrahydrofolate reductase, methionine synthetase, and methylenetetrahydrofolate dehydrogenase were significantly influenced by postnatal age.
 ...
PMID:Differences in liver folate enzyme patterns in premature and full term infants. 705 Aug 70

5-Methyltetrahydrofolate, the major form of folate in plasma, is a carbon donor for the remethylation of homocysteine to methionine. This form of folate is generated from 5,10-methylenetetrahydrofolate through the action of 5,10-methylenetetrahydrofolate reductase (MTHFR), a cytosolic flavoprotein. Patients with an autosomal recessive severe deficiency of MTHFR have homocystinuria and a wide range of neurological and vascular disturbances. We have recently described the isolation of a cDNA for MTHFR and the identification of two mutations in patients with severe MTHFR deficiency. We report here the characterization of seven novel mutations in this gene: six missense mutations and a 5' splice-site defect that activates a cryptic splice site in the coding sequence. We also present a preliminary analysis of the relationship between genotype and phenotype for all nine mutations identified thus far in this gene. A nonsense mutation and two missense mutations (proline to leucine and threonine to methionine) in the homozygous state are associated with extremely low activity (0%-3%) and onset of symptoms within the 1st year of age. Other missense mutations (arginine to cysteine and arginine to glutamine) are associated with higher enzyme activity and later onset of symptoms.
 ...
PMID:Seven novel mutations in the methylenetetrahydrofolate reductase gene and genotype/phenotype correlations in severe methylenetetrahydrofolate reductase deficiency. 772 58