On the mechanisms of the formation of L-alloisoleucine and the 2-hydroxy-3-methylvaleric acid stereoisomers from L-isoleucine in maple syrup urine disease patients and in normal humans.

  title={On the mechanisms of the formation of L-alloisoleucine and the 2-hydroxy-3-methylvaleric acid stereoisomers from L-isoleucine in maple syrup urine disease patients and in normal humans.},
  author={Orval A. Mamer and Mark L. J. Reimer},
  journal={The Journal of biological chemistry},
  volume={267 31},
  • O. Mamer, M. L. Reimer
  • Published 5 November 1992
  • Medicine, Chemistry
  • The Journal of biological chemistry
2-Keto-3-methylvaleric acid (KMVA) has been found not to undergo spontaneous keto-enol tautomerization in neutral aqueous solution, alone or in the presence of large concentrations of pyridoxamine or pyridoxamine-5-phosphate. This finding denies the commonly held suppositions that 3R-KMVA is derived spontaneously from 3S-KMVA in vivo, and that L-alloisoleucine is the product of the reamination of this 3R-KMVA. Evidence presented here suggests that racemization of the 3-carbon of L-isoleucine… 
Formation of L-Alloisoleucine In Vivo : An L-[13C]Isoleucine Study in Man
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A novel strategy for enzymatic synthesis of 4-hydroxyisoleucine: identification of an enzyme possessing HMKP (4-hydroxy-3-methyl-2-keto-pentanoate) aldolase activity.
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Metabolic annotation of 2-ethylhydracrylic acid.
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  • Chemistry, Medicine
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  • 2015
Elevated urinary 2-EHA in propionyl CoA carboxylase deficiency and methylmalonic aciduria results from a buildup of distal intermediates in the (S) pathway of isoleucine degradation.
Absolute configuration of the creatonotines and callimorphines, two classes of arctiid-specific pyrrolizidine alkaloids.
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  • Chemistry, Medicine
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  • 2001
It will be shown in this brief review that isoleucine is converted to alloisoleucines with conservation of a 15N label denying the intermediacy of the alpha-keto acids, and that alloisolucine arises as an unavoidable consequence of isoleUCine transamination.
Expression, purification, crystallization and preliminary X-ray analysis of 4-hydroxy-3-methyl-2-keto-pentanoate aldolase (asHPAL) from Arthrobacter simplex strain AKU 626.
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  • Biology, Medicine
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  • 2012
4-Hydroxy-3-methyl-2-keto-pentanoate aldolase (asHPAL), an enzyme used in the synthesis of (2S,3R,4S)-4-hydroxyisoleucine, was crystallized in the absence and the presence of 2-ketobutyrate as one of
Unexpected Formation of Low Amounts of (R)-Configurated anteiso-Fatty Acids in Rumen Fluid Experiments
Findings point to the existence of a further biosynthesis pathway of aFAs with different stereospecificity than the classic one using isoleucine as primer, which was previously observed in fish and cheese.
Significance of L-alloisoleucine in plasma for diagnosis of maple syrup urine disease.
The present findings indicate that plasma L-alloisoleucine above the cutoff value of 5 micromol/L is the most specific and most sensitive diagnostic marker for all forms of MSUD.