Liquid chromatography-mass spectrometry for simultaneous analyses of iminodipeptides containing an N-terminal or a C-terminal proline.

Abstract

Simultaneous analyses of synthetic iminodipeptides containing an N-terminal proline or a C-terminal proline have been demonstrated using liquid chromatography-mass spectrometry with an atmospheric pressure ionization interface system. The separation of iminodipeptides was carried out on a reversed-phase high-performance liquid chromatographic column using 0.1% aqueous trifluoroacetic acid-methanol (75:25, v/v, pH 2.0) as mobile phase. Very intense protonated molecular ions [M + H]+ of various synthetic iminodipeptides, Pro-Gly, Gly-Pro, Pro-Ala, Ala-Pro, Pro-Val, Val-Pro, Pro-Leu and Leu-Pro, were observed. Pro-Gly (Pro-X) and Gly-Pro (X-Pro) have the same protonated molecular ion (m/z 173), but the peaks of these compounds on the mass chromatograms were clearly distinguished by the differences of the retention times and mass spectra. The synthetic iminodipeptides containing an N-terminal proline added to urine samples from a patient with prolidase deficiency were also distinguished from iminodipeptides containing a C-terminal proline in urine samples from a patient with prolidase deficiency by scanning the [M + H]+ ion of each iminodipeptide. We established the method to measure simultaneously the various iminodipeptides containing an N-terminal or a C-terminal proline in biological samples.

• Authors: K Sugahara, H Kodama
• Journal: Journal of chromatography (J Chromatogr) Vol. 565 Issue 1-2 Pg. 408-15 (Apr 19 1991) Netherlands
• PMID: 1874885 (Publication Type: Journal Article)

Chemical References

• Dipeptides
• Proline

Topics

• Amino Acid Sequence
• Dipeptides (analysis, urine)
• Gas Chromatography-Mass Spectrometry (methods)
• Humans
• Proline (analysis, urine)