Identification of novel antimicrobial peptide from Asian sea bass (Lates calcarifer) by in silico and activity characterization

Abstract

BackgroundThe global crisis of antibiotic resistance increases the demand for the new promising alternative drugs such as antimicrobial peptides (AMPs). Accordingly, we have described a new, previously unrecognized effective AMP, named dicentracin-like, from Asian sea bass and characterized its antimicrobial activity by comparison with moronecidin.Methodology/ ResultsGene expression analysis demonstrated the expression of dicentracin-like peptide in tissues of the immune system such as the skin and the head kidney, which is an important endocrine and lymphoid organ. Moronecidin and dicentracin-like exhibited a higher antibacterial activity against gram-positive bacteria relative to gram-negative ones, while both peptides showed a greater binding ability to gram-negative bacteria compared to gram-positive ones. This contradiction between antibacterial activity and binding affinity may be related to the outer membrane from gram-negative bacteria. Compared with moronecidin, dicentracin-like peptide showed more potent binding ability to all gram-positive and gram-negative bacteria. In addition, dicentracin-like peptide exhibited a high antibacterial activity against the investigated microorganisms, except against Staphylococcus aureus. A direct relationship was found between the binding affinity/cationicity and the antibiofilm activity of the peptides wherein, an elevation in pH corresponded to a decrease in their antibiofilm property. Time-kill kinetics analysis against clinical Acinetobacter baumannii isolate indicated that bactericidal effect of dicentracin-like and moronecidin at inhibitory concentration (1XMIC) was observed after 4 and 6 hours, respectively, while bactericidal effect of both AMPs at concentration of 2XMIC was observed after 2 hours. Dicentracin-like peptide showed higher inhibitory activity at subinhibitory concentration (1/2XMIC), relative to moronecidin. Compared with moronecidin, dicentracin-like peptide possessed greater binding affinity to bacteria at high salt concentration, as well as at alkaline pH; In addition, dicentracin-like exhibited a higher antibiofilm activity in comparison to moronecidin even at alkaline pH. Hemolytic analysis against human RBC revealed that hemolytic activity of moronecidin was more potent than that of dicentracin-like, which is consistent with its greater non-polar face hydrophobicity.ConclusionsIn the present study, In Silico comparative sequence analysis and antimicrobial characterization led to identify a new, previously unrecognized antimicrobial function for named dicentracin-like peptide by comparison with moronecidin, representing a possible template for designing new effective AMPs and improving known ones.

Histidine‐Mediated Ion Specific Effects Enable Salt Tolerance of a Pore‐Forming Marine Antimicrobial Peptide

“…S. epidermidis precipitates at 500 mM NaCl, whereas the growth of S. aureus decreases as NaCl concentration increases. Therefore, the bacteria were first allowed to adapt to growing in high salt levels by repeated growth in increasing NaCl concentrations [15] . Once adapted, the bacteria grew to similar density overnight as measured by OD 600 in NaCl concentrations of 100–500 mM.…”

Dicentracin-Like from Asian sea bass Fish and Moronecidine-Like from Hippocampus Comes: Two Candidate Antimicrobial Peptides Against Leishmanina major Infection

“…In the current study, we compared the anti-L. major activities of the three AMPs dicentracine-like, moronecidin-like, and piscidin (Mohammadi et al 2018;Taheri et al 2018). The three AMPs exhibit dose dependent activity against L. major promastigotes, with piscidin being the most efficacious one as compared to the other two peptides, and induced promastigote lysis at a high peptide concentration.…”

“…In our previous study, we characterized two novel antimicrobial peptides, called moronecidin-like (from Asian sea bass fish) and moronecidine-like (from hippocampus comes) peptides, which exhibited efficient antibacterial activity against both gram-positive and gram negative bacteria, and their antibacterial activities were somewhat dependent on electrostatic interactions with bacterial cell walls (Mohammadi et al 2018;Taheri et al 2018). In this study, we evaluated the anti-Leishmania properties of moronecidin-like and dicentracin-like AMPs against promastigotes and intracellular amastigotes of L. major cultured in macrophages, in comparison to the well-characterized AMP piscidin.…”

Antiseptic 9-Meric Peptide with Potency against Carbapenem-Resistant Acinetobacter baumannii Infection

“…The effects of peptides on biofilm inhibition of A. baumannii and CRAB C0 strains were performed as described previously [73]. Briefly, bacterial cells (2 × 10 5 CFU/mL in MH media containing 0.2% (w/v) glucose) were exposed with varying concentrations (0-64 µM) of peptides, melittin, imipenem and meropenem for 16 h at 37 • C. After treatment, bacterial cells were fixed with methanol (100%, 15 min) followed by crystal violet staining (0.1% (w/v) in 0.25% (v/v) acetic acid for 1 h).…”