Innovations in generation and analysis of 2D [(13)C,(1)H] COSY NMR spectra for metabolic flux analysis purposes

Metab Eng. 2001 Oct;3(4):322-43. doi: 10.1006/mben.2001.0193.

Abstract

2D [(13)C,(1)H] COSY NMR is used by the metabolic engineering community for determining (13)C-(13)C connectivities in intracellular compounds that contain information regarding the steady-state fluxes in cellular metabolism. This paper proposes innovations in the generation and analysis of these specific NMR spectra. These include a computer tool that allows accurate determination of the relative peak areas and their complete covariance matrices even in very complex spectra. Additionally, a method is introduced for correcting the results for isotopic non-steady-state conditions. The proposed methods were applied to measured 2D [(13)C,(1)H] COSY NMR spectra. Peak intensities in a one-dimensional section of the spectrum are frequently not representative for relative peak volumes in the two-dimensional spectrum. It is shown that for some spectra a significant amount of additional information can be gained from long-range (13)C-(13)C scalar couplings in 2D [(13)C,(1)H] COSY NMR spectra. Finally, the NMR resolution enhancement by dissolving amino acid derivatives in a nonpolar solvent is demonstrated.

MeSH terms

  • Amino Acids / metabolism*
  • Carbon Isotopes
  • Magnetic Resonance Spectroscopy*

Substances

  • Amino Acids
  • Carbon Isotopes