Purificação, caracterização bioquímica e efeito na inibição de biofilme bacteriano de uma lectina presente na esponja marinha chondrilla caribensis

Abstract

The sponges are included in the phylum Porífera, are sessile, filtering and multicellular animals. They have great biotechnological and pharmacological potential. Several compounds have been discovered in these animals, such as metabolites with anti-inflammatory activity, antimicrobial activity, antitumor activity, antifouling activity, cytotoxic activity and lectin. Lectins can be defined as proteins or glycoproteins that bind reversibly to carbohydrates and are capable of binding erythrocytes and other cell types and / or precipitating polysaccharides. Marine sponges are considered a rich source of lectins, with great biotechnological potential. Thus, the objective of the present work was to purify, characterize biochemically and evaluate the effect on bacterial biofilm inhibition of an isolated lectin in the marine sponge Chodrilla caribensis from the coast of Ceará. CCL (Chodrilla caribensis lectin) was purified from the combination of ion exchange chromatography and affinity chromatography. The new lectin is a glycoprotein, with a content of 5.2% carbohydrate and a size of approximately 15 kDa. CCL showed affinity for lactose, its activity was better at pH in the neutral-alkaline range and the protein only lost its activity completely when heated to 100 ° C. The theoretical secondary structure of CCL consisted of 10.4% of α-helix, 73.4% of β-structure and 16.2% of unstructured region. In addition, the CCL was crystallized through the preliminary crystallization test. The protein was highly toxic against Artemia sp. Nauplii, presenting an LC 50 = 6.3 μg.mL-1 and was effective in inhibiting the biofilm formation of Gram-positive bacteria, S. aureus and S. epidermidis. Regarding the number of viable cells, CCL was effective only in treatment with S. epidermidis, at all concentrations.