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

PLOS ONE, Oct 2018

Background The 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/ Results Gene 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. Conclusions In 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.

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

October Identification of novel antimicrobial peptide from Asian sea bass (Lates calcarifer) by in silico and activity characterization Behrouz Taheri 0 1 2 Mohsen MohammadiID 1 2 Iraj Nabipour 1 2 Niloofar Momenzadeh 1 2 Mona Roozbehani 1 2 0 Department of Medical Laboratory Sciences, School of Paramedicine, Ahvaz Jundishapur University of Medical Sciences , Ahvaz , Iran , 2 The Persian Gulf Marine Biotechnology Research Center, the Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences , Bushehr , Iran , 3 PhD Students of Medical Parasitology School of Medicine, Iran University of Medical Sciences , Tehran , Iran 1 Editor: Anirban Bhunia, Bose Institute , INDIA 2 to MM from Bushehr University of Medical Science , Bushehr , Iran ( The 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. - Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Competing interests: The authors have declared that no competing interests exist. Background Gene 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. Timekill 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. Conclusions In 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. Introduction Antibiotic agents are effective compounds to eradicate pathogenic bacteria, consequently leading to the treatment of these infections caused by these pathogens. In the past years, the emergence of multi-drug resistant pathogens has reduced therapeutic efficiency of classical antibiotics [ 1?3 ]. To fight against drug resistant pathogens, there is an urgent demand for the discovery of novel antibiotics [ 4 ]. Antimicrobial peptides have attracted considerable attention owing to their broad-spectrum antibacterial activity and their ubiquitous presence as a part of the host defense systems in both invertebrates and vertebrates [ 5?7 ]. In contrast to conventional antibiotics, most of the AMPs exert their antibacterial activity without the need for binding to a specific ligand. These AMPs disrupt membrane integrity through pore formation in the cell membrane. Furthermore, some of them can prevent proteins and nucleic acids synthesis in bacteria through inhibition of certain enzymes involved in these processes, [ 8, 9 ]. Innate immunity is very vital for vertebrates with less efficient adaptive immunities, especially those with exposure to a wide range of pathogens such as fish and amphibians. Fish as a rich sources of AMPs, expresses major classes of AMPs including pleurocidins, and (...truncated)


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Behrouz Taheri, Mohsen Mohammadi, Iraj Nabipour, Niloofar Momenzadeh, Mona Roozbehani. Identification of novel antimicrobial peptide from Asian sea bass (Lates calcarifer) by in silico and activity characterization, PLOS ONE, 2018, Volume 13, Issue 10, DOI: 10.1371/journal.pone.0206578