Isolation and Characterization AMPs-like Peptides from Philosamia ricini Hemolymph in Response to Escherichia coli Infection

BackgroundA wide range of living organisms create this chemically and structurally diverse class of chemicals known as antimicrobial peptides (AMPs), which are primarily expressed in the areas most vulnerable to microbial invasion. Insects produce highest natural sources of AMPs. Antibiotic-resistant microorganisms are causing a global health and societal crisis.PurposeIt is necessary to design alternative drugs, using antimicrobial peptides is essential. Interest in AMPs has increased recently as a result of the rise of bacterial strains resistant to antibiotics.MethodsIn this work, the hemolymph of Philosamia ricini larvae was infected with Escherichia coli (ATCC 25922). The peptide faction was extracted using 90:1:9 methanol, acetic acid and water mixture. Reverse Phase High Liquid Chromatography (RP-HPLC) was use to purify the peptide and the obtained peptide fractions were collected, lyophilized and antimicrobial activity of the same were examined. The peptide fractions exhibiting antibacterial properties were subjected to Matrix Assisted Laser Desorption/Ionization- Time of Flight (MALDI-TOF).ResultsA Linear alpha-helical peptides (GWKDWLKKGKKAKGPGIVKAALQAATQ) and (GWKDWAKKAGGKKKGPGMAKAALKAAMQ) with flexible termini were identified with MASCOT analysis, that correspond to previously reported ant venom Neoponera goeldii. The molecular masses of these peptides, which were named as Pr-ponericin-L1 and Pr-ponericin-L2, were 1734.080 Da and 1904.104 Da respectively, as determined by MALDI-TOF mass spectrometry. Online tools, such as CAMPR4 and CAMPR3, and were used to search the obtained sequence, which were predicted to be a natural AMP.ConclusionThis study opens up new insights for using AMPs to overcome multiple antibiotic resistant in invertebrates infected with human pathogenic bacteria.