The disturbance in 2-methylmalonate metabolism resulting in its increased urinary excretion observed in vitamin E deficiency is not caused by increased formation of methylmalonate from propionate as is evident from the activity of the enzyme propionyl-CoA carboxylase (EC 184.108.40.206), but can be traced to an impairment in the conversion of methylmalonate into succinate by the vitamin B12-requiring enzyme, methylmalonyl-CoA mutase (EC 220.127.116.11) in rat liver. It is shown that the decrease in the activity of methylmalonyl-CoA mutase in vitamin E deficiency is not a consequence of a secondary vitamin B12 deficiency. Peroxidative destruction of the coenzyme in vitamin E deficiency was also ruled out. The results suggest a defect in the conversion of cyanocobalamin into its coenzyme form.
|Original language||English (US)|
|Number of pages||7|
|Publication status||Published - 1978|
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