15N-cholamine--a smart isotope tag for combining NMR- and MS-based metabolite profiling

Anal Chem. 2013 Sep 17;85(18):8715-21. doi: 10.1021/ac401712a. Epub 2013 Aug 26.

Abstract

Recently, the enhanced resolution and sensitivity offered by chemoselective isotope tags have enabled new and enhanced methods for detecting hundreds of quantifiable metabolites in biofluids using nuclear magnetic resonance (NMR) spectroscopy or mass spectrometry. However, the inability to effectively detect the same metabolites using both complementary analytical techniques has hindered the correlation of data derived from the two powerful platforms and thereby the maximization of their combined strengths for applications such as biomarker discovery and the identification of unknown metabolites. With the goal of alleviating this bottleneck, we describe a smart isotope tag, (15)N-cholamine, which possesses two important properties: an NMR sensitive isotope and a permanent charge for MS sensitivity. Using this tag, we demonstrate the detection of carboxyl group containing metabolites in both human serum and urine. By combining the individual strengths of the (15)N label and permanent charge, the smart isotope tag facilitates effective detection of the carboxyl-containing metabolome by both analytical methods. This study demonstrates a unique approach to exploit the combined strength of MS and NMR in the field of metabolomics.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Humans
  • Magnetic Resonance Spectroscopy / methods*
  • Mass Spectrometry / methods*
  • Metabolome / physiology*
  • Metabolomics / methods*
  • Nitrogen Isotopes
  • Trimethyl Ammonium Compounds / chemistry*

Substances

  • Nitrogen Isotopes
  • Trimethyl Ammonium Compounds
  • cholamine