Structural and biological characterization of Nattectin, a new C-type lectin from the venomous fish Thalassophryne nattereri

Lectins are glycan-binding receptors that recognize glycan epitopes on foreign pathogens and in the host systems. They can be involved in functions that include innate immunity, development, immune regulation and homeostasis. Several lectins have been purified and characterized from fish species. In this work, using cation-exchange chromatography, a galactose-specific lectin belonging to the family of C-type lectins was isolated from the venom of the Brazilian venomous fish Thalassophryne nattereri. Nattectin is a basic, non-glycosilated, 15 kDa monomeric protein. It exhibits hemagglutination activity that is independent of Ca2+. We also demonstrated a lectin activity for Nattectin in the innate immune system, especially in neutrophil mobilization in mice, indicating that marine organisms are source of immunomodulator agents. ► Fish lectins have been extensively described within tissues and cells associated with host defensive functions. ► Few reports describe the isolation of C-type lectins in venom of venomous fish. ► In this work we isolated and characterized a galactose-specific lectin, Nattectin in the venom of Brazilian venomous fish, that is known by the severity of the accidents provoked in fishermen and bathers. ► Nattectin is a basic, non-glycosilated, 15 kDa monomeric protein that exhibits hemagglutination activity that is independent of Ca2+. ► We also demonstrated a lectin activity for Nattectin in the innate immune system, especially in neutrophil mobilization in mice, indicating that marine organisms are source of immunomodulator agents.