Shin YS, Beuhring KU, Stokstad EL. The relationships between vitamin B12 and folic acid and the effect of methionine on folate metabolism.
Mol Cell Biochem 1975;
9:97-108. [PMID:
1196303 DOI:
10.1007/bf01732201]
[Citation(s) in RCA: 30] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The relationship between vitamin B12 and folate and the effect of methionine on folate metabolism during B12 deficiency in rats is best explained by the prevention of the accumulation of 5-methyl-H4PteGlu by vitamin B12 and/or methionine. Although several points remain to be clarified, the 'methyl trap' hypothesis provides the most satisfactory explanation for the relation between vitamin B12, methionine and folic acid. This concept is extended by the hypothesis that H4PteGlu is the most active substrate for pteroylpolyglutamate synthetase, and thus accounts for the effect of methionine or vitamin B12 increasing liver folate levels.
Collapse