Application of a Combined Peptidomics and In Silico Approach for the Identification of Novel Dipeptidyl Peptidase-IV-Inhibitory Peptides in In Vitro Digested Pinto Bean Protein Extract

Antioxidant Peptides from Sacha Inchi Meal: An In Vitro, Ex Vivo, and In Silico Approach

Plant-derived antioxidant peptides safeguard food against oxidation, helping to preserve its flavor and nutrients, and hold significant potential for use in functional food development. Sacha Inchi Oil Press-Cake (SIPC), a by-product of oil processing, was used to produce Sacha Inchi Protein Concentrate (SPC) in vitro, hydrolyzed by a standardized static INFOGEST 2.0 protocol. This study aimed to integrate in vitro, ex vivo, and in silico methods to evaluate the release of antioxidant peptides from SPC during gastrointestinal digestion. In vitro and ex vivo methods were used to investigate the antioxidant potential of SPC digests. Bioinformatics tools (find-pep-seq, AnOxPP, AnOxPePred-1.0, PepCalc, MLCPP 2.0, Pasta 2.0, PlifePred, Rapid Peptide Generator, and SwissADME) were employed to characterize antioxidant peptides. The gastric and intestinal digests exhibited higher ABTS and ORAC values than those of SPC. Under basal conditions, gastric digest fractions GD1, GD2, and GD3 (<3, 3-10, and >10 kDa, respectively), separated by ultrafiltration, significantly reduced the ROS levels in the RAW264.7 macrophages while, under LPS stimulation, GD1 (16 µg/mL) and GD2 (500 and 1000 µg/mL) reversed the induced damage. From the de novo peptidome determined, 416 peptides were selected based on their resistance to digestion. Through in silico tools, 315 resistant peptides were identified as antioxidants. Despite low predicted bioavailability, the peptides SVMGPYYNSK, EWGGGGCGGGGGVSSLR, RHWLPR, LQDWYDK, and ALEETNYELEK showed potential for extracellular targets and drug delivery. In silico digestion yielded the sequences SVMGPY, EW, GGGGCGGGGGVSS, PQY, HGGGGGG, GGGG, HW, and SGGGY, which are promising free radical scavengers with increased bioavailability. However, these hypotheses require confirmation through chemical synthesis and further validation studies.

Virtual Screening of Peptide Libraries: The Search for Peptide-Based Therapeutics Using Computational Tools

Over the last few decades, we have witnessed growing interest from both academic and industrial laboratories in peptides as possible therapeutics. Bioactive peptides have a high potential to treat various diseases with specificity and biological safety. Compared to small molecules, peptides represent better candidates as inhibitors (or general modulators) of key protein-protein interactions. In fact, undruggable proteins containing large and smooth surfaces can be more easily targeted with the conformational plasticity of peptides. The discovery of bioactive peptides, working against disease-relevant protein targets, generally requires the high-throughput screening of large libraries, and in silico approaches are highly exploited for their low-cost incidence and efficiency. The present review reports on the potential challenges linked to the employment of peptides as therapeutics and describes computational approaches, mainly structure-based virtual screening (SBVS), to support the identification of novel peptides for therapeutic implementations. Cutting-edge SBVS strategies are reviewed along with examples of applications focused on diverse classes of bioactive peptides (i.e., anticancer, antimicrobial/antiviral peptides, peptides blocking amyloid fiber formation).

Protection against Oxidative Stress and Metabolic Alterations by Synthetic Peptides Derived from Erythrina edulis Seed Protein

The ability of multifunctional food-derived peptides to act on different body targets make them promising alternatives in the prevention/management of chronic disorders. The potential of Erythrina edulis (pajuro) protein as a source of multifunctional peptides was proven. Fourteen selected synthetic peptides identified in an alcalase hydrolyzate from pajuro protein showed in vitro antioxidant, anti-hypertensive, anti-diabetic, and/or anti-obesity effects. The radical scavenging properties of the peptides could be responsible for the potent protective effects observed against the oxidative damage caused by FeSO4 in neuroblastoma cells. Moreover, their affinity towards the binding cavity of angiotensin-converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV) were predicted by molecular modeling. The results demonstrated that some peptides such as YPSY exhibited promising binding at both enzymes, supporting the role of pajuro protein as a novel ingredient of functional foods or nutraceuticals for prevention/management of oxidative stress, hypertension, and metabolic-alteration-associated chronic diseases.