Antimicrobial Activity of Molluscan Hemocyanins from Helix and Rapana Snails

Abstract

For the first time the antimicrobial activities of hemocyanins from the molluscs Rapana venosa (RvH) and Helix aspersa (HaH) have been tested. From the hemolymph of the garden snail H. aspersa one structural subunit (βc-HaH ) and eight functional units (FUs, βc-HaH-a to βc-HaH-h) were isolated, and their N-terminal sequences and molecular weights, ranging between 45 and 65 kDa, determined. The antimicrobial test of the hemocyanins against different bacteria showed that only two FUs from Rapana, RvH1-b and RvH1-e, exhibit a low inhibition effect against Staphylococcus aureus. In contrast and surprisingly, the structural subunit βc-HaH of H. aspersa not only shows strong antimicrobial activities against S. aureus and the likewise Gram-positive Streptococcus epidermidis, but also against the Gram-negative bacterium Escherichia coli. We suggest that this subunit therefore has the potential to become a substitute for the commonly used antibiotics against which bacterial resistance has gradually been developed.

Differential Protein Expression in the Hemolymph of Bithynia siamensis goniomphalos Infected with Opisthorchis viverrini

“…HMC is the main protein component of hemolymph, and is found in both hemocyte and plasma. The function HMC in invertebrate is not only as a respiratory protein via oxygen transport, but it has also been strongly associated with different immunological processes [60–66]. HMC has been shown to participate in multiple roles of the immune response including phenoloxidase activity [61–64], antiviral [65] and antimicrobial activity [66].…”

Immunological properties of oxygen-transport proteins: hemoglobin, hemocyanin and hemerythrin

“…Although diverse antimicrobial and antiviral properties of mollusc Hc oligomers and several FUs have been noted [21, 184–186], mollusc Hc-derived peptides have received little attention. An interrogation of whelk ( Rapana venosa ) hemolymph led to the identification of a peptide with sequence similarities to a conserved motif at the N-terminus of many Hc FUs [185].…”

Marine Snails and Slugs: a Great Place To Look for Antiviral Drugs

“…Hemocyanin antiviral activity has been attributed to glycosylated sites (27,32,51,52). It was previously suggested that hemocyanin carbohydrate chains interact with surface-exposed amino acid or carbohydrate residues of the viruses through van der Waals interactions (53). Despite hemocyanins having been found to be associated with arthropod antiviral immunity due to their increased expression upon viral infection (54,55) and the finding that their antiviral activity is effective against their own arthropod viruses (56,57), the role of hemocyanins in molluscan immunity remains unclear.…”