Interrelation between the metabolism of L-isoleucine and L-allo-isoleucine in patients with maple syrup urine disease

Pediatr Res. 1989 Jan;25(1):11-4. doi: 10.1203/00006450-198901000-00003.

Abstract

The nonprotein amino acid L-allo-isoleucine is formed endogenously in maple syrup urine disease patients from (R)-3-methyl-2-oxo-pentanoic acid. During strict metabolic balance, the plasma L-allo-isoleucine/L-isoleucine ratio correlates inversely with the residual activity of the branched-chain 2-oxoacid dehydrogenase in fibroblasts and thus constitutes a relevant in vivo parameter of the severity of the metabolic defect in MSUD patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)
  • Chemical Phenomena
  • Chemistry
  • Child, Preschool
  • Female
  • Fibroblasts / enzymology
  • Humans
  • Infant
  • Infant, Newborn
  • Isoleucine / blood*
  • Isomerism
  • Ketone Oxidoreductases / metabolism
  • Kinetics
  • Male
  • Maple Syrup Urine Disease / diagnosis
  • Maple Syrup Urine Disease / metabolism*
  • Multienzyme Complexes / metabolism

Substances

  • Multienzyme Complexes
  • Isoleucine
  • Ketone Oxidoreductases
  • 3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)