Global Profiling of Post-Translationally Modified Crustacean Neuropeptidome Trends Affiliated with Feeding Activity

Neuropeptides modulate a diverse range of physiological functions, including those associated with feeding. Post-translational modifications (PTMs) contribute significantly to the dynamic nature of neuropeptide isoforms, influencing their functional diversity. Mass spectrometry is the gold-standard analytical technique for peptidomic analyses and is complemented by computational methods for peptide identification; however, the computational search space becomes increasingly difficult to manage as more potential modifications are considered. Using innovative approaches capable of addressing the vast combinations of possible modifications, such as the PEAKS PTM search algorithm, we globally profiled the neuropeptidome ofCancer borealis(Jonah crab) to investigate the role of PTMs in feeding- and appetite-related processes over time. Through an in-depth examination of several notable modifications, we proposed PTM-associated motifs for neuropeptides, which may enhance future identification capabilities. Furthermore, this work revealed neuropeptides that were characteristically modified depending on the crab's feeding status and time post-feeding, suggesting potential biological significance. This study represents the first large-scale investigation of the modified crustacean neuropeptidome, providing new insights into the regulatory implications of PTMs in biological systems.