Analytical and Bioanalytical Chemistry

, Volume 405, Issue 5, pp 1721–1732

Scrambling of autoinducing precursor peptides investigated by infrared multiphoton dissociation with electrospray ionization and Fourier transform ion cyclotron resonance mass spectrometry

  • Giuliana Bianco
  • Cristiana Labella
  • Antonietta Pepe
  • Tommaso R. I. Cataldi
Original Paper

DOI: 10.1007/s00216-012-6583-5

Cite this article as:
Bianco, G., Labella, C., Pepe, A. et al. Anal Bioanal Chem (2013) 405: 1721. doi:10.1007/s00216-012-6583-5


Two synthetic precursor peptides, H2N-CVGIW and H2N-LVMCCVGIW, involved in the quorum sensing of Lactobacillus plantarum WCFS1, were characterized by mass spectrometry (MS) with electrospray ionization and 7-T Fourier transform ion cyclotron resonance (ESI-FTICR) instrument. Cell-free bacterial supernatant solutions were analyzed by reversed-phase liquid chromatography with ESI-FTICR MS to verify the occurrence of both pentapeptide and nonapeptide in the bacterial broth. The structural characterization of both protonated peptides was performed by infrared multiphoton dissociation using a continuous CO2 laser source at a wavelength of 10.6 μm. As their fragmentation behavior cannot be directly derived from the primary peptide structure, all anomalous fragments were interpreted as neutral loss of amino acids from the interior of both peptides, i.e., loss of V, G, VG and M, MC, V, CC, from H2N-CVGIW and H2N-LVMCCVGIW, respectively. Mechanisms of this scrambling are proposed. FTICR MS provides accurate masses of all fragment ions with very low absolute mass errors (<1.6 ppm), which facilitated the reliable assignment of their elemental compositions. The resolving power was more than sufficient to resolve closely isobaric product ions with routine subparts per million mass accuracies. Only the occurrence of pentapeptide was found in the cell-free culture of L. plantarum, grown in Waymouth’s medium broth, with a low content of 5.2 ± 2.6 μM by external calibration. Most of it was present as oxidized H2N-CVGIW, that is, the soluble disulfide pentapeptide with a level tenfold higher (i.e., 50 ± 4 μM, n = 3).

IRMPD of the precursor protonated peptide, [H2N-CVGIW +H]+ at m/z 577.3 and suggested pathway showing the formation of peptide macrocycle and its selective ring opening.


Autoinducing peptidesInfrared multiphoton dissociation (IRMPD)Tandem MSPeptide fragmentationScrambling mechanismFTICR MS (7-T)

Supplementary material

216_2012_6583_MOESM1_ESM.pdf (1.2 mb)
ESM 1(PDF 1180 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Giuliana Bianco
    • 1
    • 3
  • Cristiana Labella
    • 1
  • Antonietta Pepe
    • 1
  • Tommaso R. I. Cataldi
    • 2
    • 4
  1. 1.Dipartimento di ScienzeUniversità degli Studi della BasilicataPotenzaItaly
  2. 2.Dipartimento di ChimicaUniversità degli Studi di Bari Aldo Moro, Campus UniversitarioBariItaly
  3. 3.Centro Interdipartimentale CIGASUniversità degli Studi della BasilicataPotenzaItaly
  4. 4.Centro Interdipartimentale SMARTUniversità degli Studi di Bari Aldo Moro, Campus UniversitarioBariItaly