Linked Life Data

10674358

Source:http://linkedlifedata.com/resource/pubmed/id/10674358

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2000-3-30
pubmed:abstractText
L-alloisoleucine (2S, 3R), a diastereomer of L-isoleucine (2S, 3S), is a normal constituent of human plasma. Considerable amounts accumulate in maple syrup urine disease, in which the branched-chain 2-oxo acid dehydrogenase step is impaired. The mechanism of L-alloisoleucine formation, however, is unclear. We addressed this issue by performing oral L-[1-13C]isoleucine loading (38 micromol/kg body wt, 50% 1-13C) in overnight-fasted healthy subjects (n = 4) and measuring the 3-h kinetics of 13C-label incorporation into L-isoleucine plasma metabolites. Compared with L-isoleucine, the time course of 13C-enrichment in the related 2-oxo acid, S-3-methyl-2-oxopentanoate, was only slightly delayed. Peak values, amounting to 18+/-4 and 17+/-3 mol percent excess, respectively, were reached within 35 and 45 min, respectively. The kinetics of 13C-enrichment in S- and R-3-methyl-2-oxopentanoate enantiomorphs were similar and linearly correlated (p << 0.001). In L-alloisoleucine, however, 13C-label accumulated only gradually and in minor amounts. Our results indicate that R-3-methyl-2-oxopentanoate is an immediate and inevitable byproduct of L-isoleucine transamination and further suggest that alloisoleucine is primarily formed via retransamination of 3-methyl-2-oxopenanoate in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0031-3998
pubmed:author
pubmed:issnType
Print
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
271-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Formation of L-alloisoleucine in vivo: an L-[13C]isoleucine study in man.
pubmed:affiliation
Diabetes Forschungsinstitut, Heinrich-Heine-Universität Düsseldorf, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't