Characterization of a Novel Antimicrobial Peptide Isolated from Moringa oleifera Seed Protein Hydrolysates and Its Membrane Damaging Effects on Staphylococcus aureus

Abstract

The present study sought to identify and characterize a novel antimicrobial peptide, named MOp2 from Moringa oleifera seed protein hydrolysates, and elucidate its potential antimicrobial effects on Staphylococcus aureus. MOp2, with the amino acid sequence of His−Val−Leu−Asp−Thr−Pro−Leu−Leu (HVLDTPLL), was characterized as a hydrophobic anionic AMP of the β-sheet structure. MOp2 exhibited negligible hemolytic activity at 2.0× MIC, suggesting its inhibitory effect on the growth of S. aureus (MIC: 2.204 mM). It maintained more than 90% of antimicrobial activity under 5% salt and about 78% of antimicrobial activity at a high temperature of 115 °C for 30 min. Protease, especially acid protease, reduced its antimicrobial activity to different extents. Moreover, MOp2 caused irreversible membrane damage to S. aureus cells by increasing the membrane permeability, resulting in the release of intracellular nucleotide pools. Additionally, molecular docking revealed that MOp2 could inhibit S. aureus growth by interacting with dihydrofolate reductase and DNA gyrase through hydrogen bonding and hydrophobic interactions. Overall, MOp2 could be a potential novel antimicrobial agent against S. aureus in food processing.

Anti-Salmonella Activity of a Novel Peptide, KGGDLGLFEPTL, Derived from Egg Yolk Hydrolysate

“…Few anionic AMPs have been reported. Zhao et al [37] reported that anionic AMP, HVLDTPLL, isolated from hydrolysates of Moringa oleifera seed proteins, displayed activity against S. Typhimurium CICC 21484 at 4.4 mM RVAPEEHPTL and FFTQATDLLSR, which were anionic AMPs derived from Maillard reaction products and inhibited the growth of Escherichia coli at approximately 17 and 15 mM, respectively [38]. These reported peptides showed less effective antimicrobial activity than the EYHp6 reported in our study.…”

Chickpea-Derived Modified Antimicrobial Peptides KTA and KTR Inactivate Staphylococcus aureus via Disrupting Cell Membrane and Interfering with Peptidoglycan Synthesis

“…However, the degree of α-helix varied due to one different amino acid in the sequence. This difference of secondary structure may have an effect on the bacterial targeting specificity of AMPs . Furthermore, Figure S1 showed that the surface of the peptides was positively charged as predicted with a theoretical pI greater than 7.0 (Table ), attributed to arginine and lysine in the amino acid sequence.…”

“…This difference of secondary structure may have an effect on the bacterial targeting specificity of AMPs. 35 Furthermore, Figure S1 showed that the surface of the peptides was positively charged as predicted with a theoretical pI greater than 7.0 (Table 1), attributed to arginine and lysine in the amino acid sequence. Therein, KTR was predicted to have a higher positive charge than KTA due to the presence of more arginine residues, suggesting that KTR peptides are more inclined to bind to negatively charged cell membranes through electrostatic interactions.…”

“…Accordingly, KTA was confirmed to effectively interact with the PBP2a-active sites, which shows its promising potential as an inhibitor of peptidoglycan synthesis. 11,35 Nevertheless, the bactericidal efficacy of KTR may be achieved by targeting other membrane components or other active sites in peptidoglycan. A more precise mode of action will be revealed with some further studies, such as molecular dynamics simulation and multiple omics analyses.…”

Molecular Insights into the Mode of Action of Antibacterial Peptides Derived from Chicken Plasma Hydrolysates

“…The MIC value of VSDH against S . aureus was lower than that of peptide Mop2 (HVLDTPLL) from Moringa oleifera seed protein hydrolysate at 2.2 mM [ 34 ] and SP-1 (KLVDASHRLATGDVAVRA) from the protein hydrolysate of Spirulina platensis at 8.52 mM [ 35 ]. The peptide AVDRAV, from laba garlic, showed a more effective MIC value of 0.1 mM [ 21 ].…”