Exploring the Candidate Terminal Glycan Profile in Neural Regeneration of the Sea Urchin Paracentrotus lividus, Using Lectin Blotting and Mass Spectrometry

Glycans are expressed as conjugates of glycoproteins, glycolipids, and proteoglycans. The huge diversity of glycans on glycoconjugates contributes to many biological processes, from glycan-based molecular recognition to developmental events, such as regeneration in the nervous system. Echinoderms, which have a close phylogenetic relationship with chordates, are an important group of marine invertebrates for body regeneration. Although many major roles of glycans on glycoconjugates are known, their role in the glycosylation profile of the nervous system in sea urchins is poorly understood. In this study, we aimed to determine the terminal glycan profile by lectin blotting and to quantify sialic acids by the capillary liquid chromatography electrospray ionization tandem mass spectrometry system in the nervous tissue of the sea urchin Paracentrotus lividus. We determined the N-acetyl-D-glucosamine, mannose, and sialic acids (mainly α2,3 linked) by lectin blotting and five types of sialic acids (N-glycolylneuraminic acid, N-acetylneuraminic acid, 9-O-acetyl-N-alycolylneuraminic acid, 5-N-acetyl-9-O-acetyl-N-acetylneuraminic acid, and di-O-acetylated-N-alycolylneuraminic acid) by capillary liquid chromatography electrospray ionization tandem mass spectrometry. This potential first description of the terminal glycan profile in the nervous system of the sea urchin is expected to help us understand its role in nervous system development and regeneration.