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Effect of cobalamin inactivation on folate-dependent transformylases involved in purine synthesis in rats.

ABSTRACT: N2O oxidizes and inactivates cob[I]alamin, and animals exposed in this way serve as models for cobalamin 'deficiency'. Such animals show a fall in activity of glycinamide ribotide transformylase and a rise in that of 5-amino-4-imidazolecarboxamide ribotide transformylase. The fall in glycinamide ribotide transformylase activity was prevented by parenteral 5'-methylthioadenosine derived from methionine. Methylthioadenosine in turn is converted into formate. Activity of glycinamide ribotide transformylase recovers after 7 days despite continued N2O inhalation, and this is probably related to restoration of methionine synthesis by induction of betaine:homocysteine transmethylase.

SUBMITTER: Deacon R

PROVIDER: S-EPMC1144809 | biostudies-other | 1985 Apr

REPOSITORIES: biostudies-other

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Folate depletion induces erythroid differentiation through perturbation of de novo purine synthesis

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Folate polyglutamate synthetase activity in the cobalamin-inactivated rat.

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Folate depletion induces erythroid differentiation through perturbation of de novo purine synthesis

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