Sources of Acetyl-CoA Entering the Tricarboxylic Acid Cycle As Determined by Analysis of Succinate 13C Isotopomers

John G. Jones, A. Dean Sherry, F. Mark H Jeffrey, Charles J. Storey, Craig R. Malloy

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

A new 13C NMR technique for measuring substrate utilization by the citric acid cycle based on an analysis of succinate 13C isotopomers is presented. The relative contribution of up to three different labeling patterns in acetyl-CoA entering the citric acid cycle may be determined under non-steady-state conditions. We present experimental data from perfused rat hearts subjected to a brief period of ischemia, where both succinate and glutamate resonances were observed in the 13C spectrum. The contributions of labeled exogenous acetate and lactate and unlabeled sources to the acetyl-CoA pool were compared using this succinate analysis and a previously published glutamate analysis [Malloy et al. (1990) Biochemistry 29, 6756–6761], and the two methods give identical results. This indicates that the succinate and glutamate isotopomers originated from a common α-ketoglutarate pool, verifying that glutamate is in isotopomeric equilibrium with α-ketoglutarate under these conditions.

Original languageEnglish (US)
Pages (from-to)12240-12244
Number of pages5
JournalBiochemistry
Volume32
Issue number45
DOIs
StatePublished - Jan 1 1993

ASJC Scopus subject areas

  • Biochemistry

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