New Antibacterial Peptides from the Freshwater Mollusk Pomacea poeyana (Pilsbry, 1927)

Abstract

Antimicrobial peptides (AMPs) are biomolecules with antimicrobial activity against a broad group of pathogens. In the past few decades, AMPs have represented an important alternative for the treatment of infectious diseases. Their isolation from natural sources has been widely investigated. In this sense, mollusks are promising organisms for the identification of AMPs given that their immune system mainly relies on innate response. In this report, we characterized the peptide fraction of the Cuban freshwater snail Pomacea poeyana (Pilsbry, 1927) and identified 37 different peptides by nanoLC-ESI-MS-MS technology. From these peptide sequences, using bioinformatic prediction tools, we discovered two potential antimicrobial peptides named Pom-1 (KCAGSIAWAIGSGLFGGAKLIKIKKYIAELGGLQ) and Pom-2 (KEIERAGQRIRDAIISAAPAVETLAQAQKIIKGG). Database search revealed that Pom-1 is a fragment of Closticin 574 previously isolated from the bacteria Clostridium tyrobutyrium, and Pom-2 is a fragment of cecropin D-like peptide first isolated from Galleria mellonella hemolymph. These sequences were chemically synthesized and evaluated against different human pathogens. Interestingly, structural predictions of both peptides in the presence of micelles showed models that comprise two alpha helices joined by a short loop. The CD spectra analysis of Pom-1 and Pom-2 in water showed for both structures a high random coil content, a certain content of α-helix and a low β-sheet content. Like other described AMPs displaying a disordered structure in water, the peptides may adopt a helical conformation in presence of bacterial membranes. In antimicrobial assays, Pom-1 demonstrated high activity against the Gram-negative bacteria Pseudomonas aeruginosa and moderate activity against Klebsiella pneumoniae and Listeria monocytogenes. Neither of the two peptides showed antifungal action. Pom-1 moderately inhibits Zika Virus infection but slightly enhances HIV-1 infectivion in vitro. The evaluation of cell toxicity on primary human macrophages did not show toxicity on THP-1 cells, although slight overall toxicity was observed in high concentrations of Pom-1. We assume that both peptides may play a key role in innate defense of P. poeyana and represent promising antimicrobial candidates for humans.

Antimicrobial Peptides Pom-1 and Pom-2 from Pomacea poeyana Are Active against Candidaauris, C. parapsilosis and C. albicans Biofilms

“…Standard deviations have been calculated and found to be too low to be visible in the graphs. Modelled 3D-structure of Pom-1 and Pom-2 using the QUARK and SwissModel server and the corresponding amino acid sequence [38]. The red letters represent hydrophobic amino acids and the blue hydrophilic.…”

“…Interestingly, synthetic dimeric derivatives of Cmp-5 exhibited a considerable activity towards C. auris biofilms on an abiotic substratum inhibiting the growth of biofilms but had only low activities against the respective planktonic cells compared to the original Cm-p5 [37]. Recently we have described another set of AMPs isolated from the Cuban freshwater snail Pomacea poeyana (Pilsbry, 1927) [38]. These two peptides named Pom-1 and Pom-2 demonstrated high antimicrobial activity against the Gram-negative bacteria such as Pseudomonas aeruginosa while it demonstrates only a moderate activity against Klebsiella pneumoniae and Listeria monocytogenes in combination with low toxicity towards primary human macrophages [38].…”

“…Recently we have described another set of AMPs isolated from the Cuban freshwater snail Pomacea poeyana (Pilsbry, 1927) [38]. These two peptides named Pom-1 and Pom-2 demonstrated high antimicrobial activity against the Gram-negative bacteria such as Pseudomonas aeruginosa while it demonstrates only a moderate activity against Klebsiella pneumoniae and Listeria monocytogenes in combination with low toxicity towards primary human macrophages [38].…”

Large-Scale Plasma Peptidomic Profiling Reveals a Novel, Nontoxic, Crassostrea hongkongensis-Derived Antimicrobial Peptide against Foodborne Pathogens

“…To our knowledge, ours is the first comprehensive large-scale plasma peptidomic dataset that describes a large number of endogenous peptides from marine mollusk plasma, based on mass spectrometry. Similar peptidomic analysis was performed in Freshwater Mollusk Pomacea poeyana, revealing promising antimicrobial candidates [ 25 ]. In this study, low-abundance endogenous peptides were enriched by filtering with an ultrafiltration tube with a 10 kD filter membrane from a highly complex plasma environment with proteins of large heterogeneity in sizes and charges.…”

A Dissenters’ View on AppleSnail Immunobiology

“…However, some have been reported in bivalves ( 96 , 97 ). In Ampullariidae, to our knowledge, there has been a single report in Pomacea poeyana ( 98 ).…”