Simão, M., Moco, M., Marques, L. & Santos, R. (2020) Characterization of the glycans involved in sea urchin Paracentrotus lividus reversible adhesion.Marine Biology, 167, 125. DOI:10.1007/s00227-020-03707-9 (IF2020 2,573; Q1 Marine & Freshwater Biology)
Sea urchins have hundreds of specialized adhesive organs, the tube feet, which play a key role in locomotion, substrate attachment and food capture. Tube feet are composed by two functional units: a proximal cylindrical stem that is mobile and flexible, attached to a distal flattened disc that produces adhesive secretions. Oral tube feet discs possess a specialized duo-glandular epidermis that produces adhesive and de-adhesive secretions, enabling strong but reversible adhesion to the substrate. Due to the growing interest in biomimetic adhesives, several studies have been carried out to characterize sea urchin adhesives, and up to date, it has been shown that it is composed by proteins and glycans. The protein fraction has been the subject of several studies, that pin-pointed several adhesion-related candidates. Contrastingly, little is known about the glycans that compose sea urchin adhesives. This study aims at contributing to this topic by focusing on the characterization of the glycosidic fraction of the adhesive secreted by the sea urchin Paracentrotus lividus (Lamarck, 1816), using a battery of 22 lectins, applied to 3 complementary techniques. Our results show that five lectins label exclusively the disc adhesive epidermis and simultaneously the secreted adhesive, being, therefore, most likely relevant for sea urchin adhesion. In addition, it was possible to determine that the glycosidic fraction of the adhesive is composed by a high molecular weight glycoprotein containing N-acetylglucosamine oligomers.