Gastropods are among the most diverse animals. Gastropod mucus contains several glycoproteins and peptides that vary by species and habitat. Some bioactive peptides from gastropod mucus were identified only in a few species. Therefore, using biochemical, mass spectrometric, and bioinformatics approaches, this study aimed to comprehensively identify putative bioactive peptides from the mucus proteomes of seven commonly found or commercially valuable gastropods. The mucus was collected in triplicate samples, and the proteins were separated by 1D-SDS-PAGE before tryptic digestion and peptide identification by nano LC-MS/MS. The mucus peptides were subsequently compared with R scripts. A total of 2818 different peptides constituting 1634 proteins from the mucus samples were identified, and 1218 of these peptides (43%) were core peptides found in the mucus of all examined species. Clustering and correspondence analyses of 1600 variable peptides showed unique mucous peptide patterns for each species. The high-throughput k-nearest neighbor and random forest-based prediction programs were developed with more than 95% averaged accuracy and could identify 11 functional categories of putative bioactive peptides and 268 peptides (9.5%) with at least five to seven bioactive properties. Antihypertensive, drug-delivering, and antiparasitic peptides were predominant. These peptides provide an understanding of gastropod mucus, and the putative bioactive peptides are expected to be experimentally validated for further medical, pharmaceutical, and cosmetic applications.

Currently, the use of skipjack tuna (Katsuwonus pelamis) roe to produce hydrolysate is limited, although it is a potentially valuable resource. This study aimed to investigate the physical and chemical characteristics of protein hydrolysates from tuna roe using autoclave and enzymes (alcalase and trypsin at 0.5 and 1.0% w/v). Bioinformatics was also applied to analyze the identified peptides. The hydrolysates were determined for amino acid composition, peptide profile patterns, antioxidant activity, solubility and foaming properties. The proteins were separated by SDS-PAGE before tryptic digestion and peptide identification by nano LC-ESI-MS/MS. The putative bioactivities of the identified peptides were predicted using bioinformatics prediction tools. The main amino acids found in all hydrolysates were cysteine, glycine and arginine (16.26–20.65, 10.67–13.61 and 10.87–12.08 g/100 g protein, respectively). The hydrolysates obtained from autoclaving showed lower molecular weights than those by the enzymatic method. The 0.1 g/mL concentration of hydrolysates provided higher antioxidant activities compared to the others. All hydrolysates had high solubility and exhibited foaming capacity and foam stability. Putative anti-hypertensive, anti-virus and anti-parasite activities were highly abundant within the obtained peptides. Moreover, predicted muti-bioactivity was indicated for seven novel peptides. In the future work, these peptides should be experimentally validated for further applications.