Peptidomics

Abstract

Peptides occur in the whole animal kingdom, from the least evolved phyla with a very simple nervous system (coelenterates) to the highest vertebrates and are involved in most, if not all, physiological processes in animals. Knowing the amino acid sequence of peptide hormones or neurotransmitters is important since this allows for synthesis of large quantities of peptides to perform further functional analysis. Immunocytochemistry, radioimmunoassays (RIA), enzyme-linked immunosorbant assays (ELISA) and mass spectrometry can then provide information on the temporal and spatial distribution and quantification of the (neuro)peptide. Ever since the 1970s, a wealth of peptides has been discovered and investigated and this flow seems to be far from over. This is partially due to the use of new approaches mainly based on chromatographical purifications as well as molecular biological techniques. Surprisingly, peptides have so far been neglected in most proteomic studies. The finalization of the genome projects has opened new opportunities for rapid identification and functional analysis of (neuro)peptides as well. In analogy with the proteomics technology, where all proteins expressed in a cell or tissue are analyzed, the peptidomic approach aims at the simultaneous visualization and identification of the whole peptidome of a cell or tissue, i.e. all expressed peptides with their post-translational modifications (PTMs). This technology provides us with a fast and efficient tool to analyze the peptides from any tissue. This paper reviews the approaches that have been used so far to achieve this.

Peptidomic analysis of the larval Drosophila melanogaster central nervous system by two‐dimensional capillary liquid chromatography quadrupole time‐of‐flight mass spectrometry

“…1 However, very few proteomic studies include a systematic analysis of naturally occurring peptides. 2,3 In analogy with proteomics technology, where all proteins expressed in a cell or tissue are analyzed, the peptidomic approach aims at the simultaneous visualization and identification of the whole peptidome of a cell or tissue, i.e. all expressed peptides with their post-translational modifications.…”

Peptide and protein characterization by high‐rate electron capture dissociation Fourier transform ion cyclotron resonance mass spectrometry

“…By definition, peptidomics covers the analysis of the peptidome, or the expressed peptides with post-translational modifications, of a given cell, body fluid or tissue at a given time. 67 Typically, the high complexity of the extracted peptide mixtures requires a separation stage prior to MS analysis. Further development of MS/MS techniques for peptide sequence determination and location of posttranslational modifications on the time-scale of LC separation is required.…”

Limitations of Mass Spectrometry-Based Peptidomic Approaches

“…T he development of mass spectrometry-based peptidomic techniques has revolutionized the field of peptides [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Before development of peptidomics approaches, the detection of peptides was largely performed using radioimmunoassays [16].…”

“…For the identification of unknown peptides, it was previously necessary to extensively purify each peptide in order for Edman degradation sequencing to be effective. Mass spectrometry-based peptide discovery allowed for identification of peptides in complex mixtures [1][2][3][4][5][6][7][8][11][12][13][14][15]. Quantitative peptidomic approaches facilitated the relative quantification of peptides in mixtures, including both known and previously unknown peptides.…”