Cobalamin-dependent Formation of Leucine and /?-Leucine by Rat and Human Tissue
نویسنده
چکیده
Circulating levels of 8-leucine are elevated in the cobalamin-deficient state of pernicious anemia. Levels of leucine, on the other hand, are much lower. It is proposed that leucine 2,3-aminomutase, the cobalamindependent enzyme that catalyzes the interconversion of leucine and 8-leucine, is the affected enzyme in pernicious anemia and causes these results by preventing the synthesis of leucine from 8-leucine. The synthesis of leucine by human leukocytes and hair roots and by rat liver extracts has been shown to occur when either branched chain fatty acids or valine metabolites are the substrates. The synthesis is dependent upon adenosylcobalamin and is inhibited by intrinsic factor.
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