Avaliação do potencial antibacteriano da lectina da esponja marinha Haliclona caerulea (Halilectina – 2)

Abstract

Sponges, phylum Porifera (from the Latin porus, pore + beast, bearer), are multicellular beings whose body consists of a mass of cells immersed in a gelatinous matrix and perforated by a complex system of canals. The genus Haliclona includes species widely distributed throughout the oceans, occurring at different depths and presenting a variety of colors. Throughout evolution, sponges have developed several physiological and phenotypic adaptations to maintain themselves in the marine environment. One of these adaptations was the production of metabolites, among which lectins stand out. These proteins of non-immune origin have the ability to bind specifically and reversibly to carbohydrates. Several biological activities associated with these molecules have been described, including anticancer, antiviral, antifungal and antibacterial properties. The present study aims to evaluate the antibacterial and antibiofilm potential of Halilectin (H-2), present in the sponge Haliclona caerulea. H-2 is a homodimeric protein with 15 kDa monomers interconnected by weakly interacting bonds that oligomerize to form a 29 kDa dimer. The lectin showed affinity for the glycoproteins asialofetuin, fetuin, and porcine stomach mucin type II and type III (PSM). Circular dichroism analysis demonstrated the predominant presence of β-sheet structures with spectra of β1 proteins. H-2 was able to agglutinate Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 700698, and Escherichia coli ATCC 11303 cells. The lectin showed antibacterial potential, since when associated with tetracycline, the protein potentiated the effect of the antibiotic, in addition to inhibiting biofilm formation. Thus, H-2 was shown to be a lectin with high biotechnological potential with antibacterial action in association with the antibiotic tetracycline.