Altered neuropeptide profile of Caenorhabditis elegans lacking the chaperone protein 7B2 as analyzed by mass spectrometry

Abstract 

Cellular synthesis of naturally occurring, bioactive peptides requires the proprotein convertase PC2/EGL-3 for cleavage from the larger peptide precursors. A neuroendocrine chaperone 7B2 is needed for the proteolytical activation of proPC2, as extensively studied in mouse models. To determine the role of its orthologue in Caenorhabditis elegans, we analyzed wild-type and 7B2-null strains by HPLC and matrix-assisted laser desorption ionization time-of-flight mass spectrometry, which allowed the identification of a novel neuropeptide gene, flp-33. The presence and/or absence of some neuropeptides in 7B2-null animals strongly differs form the peptide profile in wild-type, suggesting a specific and determined action of 7B2 in C. elegans.

Abbreviations: Da, Dalton, flp, FMRF amide-like peptide, m/z, mass-to-charge ratio, MALDI-TOF MS, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, MS/MS, tandem mass spectrometry, nlp, neuropeptide-like protein, PC, proprotein convertase, sbt-1, seven-B-two-1

Keywords: Neuropeptide, Peptidomics, Mass spectrometry, MALDI-TOF MS, FLP, NLP