Aquatic Peptide: The Potential Anti-Cancer and Anti-Microbial Activity of GE18 Derived from Pathogenic Fungus Aphanomyces invadans

Discovery of anticancer peptides from natural and generated sequences using deep learning

Anticancer peptides (ACPs) demonstrate significant potential in clinical cancer treatment due to their ability to selectively target and kill cancer cells. In recent years, numerous artificial intelligence (AI) algorithms have been developed. However, many predictive methods lack sufficient wet lab validation, thereby constraining the progress of models and impeding the discovery of novel ACPs. This study proposes a comprehensive research strategy by introducing CNBT-ACPred, an ACP prediction model based on a three-channel deep learning architecture, supported by extensive in vitro and in vivo experiments. CNBT-ACPred achieved an accuracy of 0.9554 and a Matthews Correlation Coefficient (MCC) of 0.8602. Compared to existing excellent models, CNBT-ACPred increased accuracy by at least 5 % and improved MCC by 15 %. Predictions were conducted on over 3.8 million sequences from Uniprot, along with 100,000 sequences generated by a deep generative model, ultimately identifying 37 out of 41 candidate peptides from >30 species that exhibited effective in vitro tumor inhibitory activity. Among these, tPep14 demonstrated significant anticancer effects in two mouse xenograft models without detectable toxicity. Finally, the study revealed correlations between the amino acid composition, structure, and function of the identified ACP candidates.

DbGTi: Thermostable trypsin inhibitor from Dioscorea bulbifera L. ground tubers: assessment of antioxidant and antibacterial properties and cytotoxicity evaluation using zebrafish model

Oxidative stress disorders and diseases caused by drug-resistant bacteria have emerged as significant public health concerns. Plant-based medications like protease inhibitors are growing despite adverse effects therapies. Consecutively, in this study, trypsin inhibitors from Dioscorea bulbifera L. (DbGTi trypsin inhibitor) ground tubers were isolated, purified, characterized, and evaluated for their potential cytotoxicity, antibacterial, and antioxidant activities. DbGTi protein was purified by Q-Sepharose matrix, followed by trypsin inhibitory activity. The molecular weight of the DbGTi protein was found to be approximately 31 kDa by SDS-PAGE electrophoresis. The secondary structure analysis by circular dichroism (CD) spectroscopy revealed that the DbGTi protein predominantly comprises β sheets followed by α helix. DbGTi protein showed competitive type of inhibition with Vmax = 2.1372 × 10-1 μM/min, Km = 1.1805 × 102 μM, & Ki = 8.4 × 10-9 M and was stable up to 70 °C. DbGTi protein exhibited 58 % similarity with Dioscorin protein isolated from Dioscorea alata L. as revealed by LC-MS/MS analysis. DbGTi protein showed a non-toxic effect, analyzed by MTT, Haemolytic assay and in vivo studies on zebrafish model. DbGTi protein significantly inhibited K. pneumoniae and has excellent antioxidant properties, confirmed by various antioxidant assays. The results of anti-microbial, cytotoxicity and antioxidant assays demonstrate its bioactive potential and non-toxic nature.

Characterization of a Novel Antimicrobial Peptide Bacipeptin against Foodborne Pathogens

The increasing emergence of multidrug-resistant pathogens and development of biopreservatives in food industries has increased the demand of novel and safe antimicrobial agents. In this study, a marine bacterial strain Bacillus licheniformis M1 was isolated and exhibited obvious antimicrobial activities against foodborne pathogens, especially against methicillin-resistant Staphylococcus aureus. The antimicrobial agent was purified and identified as a novel antimicrobial peptide, which was designated as bacipeptin, and the corresponding mechanism was further investigated by electron microscopy observation and transcriptomic analysis with biochemical validation. The results showed that bacipeptin could reduce the virulence of methicillin-resistant Staphylococcus aureus and exerted its antimicrobial activity by interfering with histidine metabolism, inducing the accumulation of reactive oxygen species and down-regulating genes related to Na+/H+ antiporter and the cell wall, thus causing damage to the cell wall and membrane. Overall, our study provides a novel natural product against foodborne pathogens and discloses the corresponding action mechanism.