Characterization of three sialidases from Danio rerio

Zebrafish encodes several sialidases belonging to the NEU3 group, plasma membrane-associated member of family with high specificity toward ganglioside substrates. Neu3.1, Neu3.2 and Neu 3.3 have been expressed in E. coli purified using pGEX-2T expression system. Although all enzymes are by bacterial cells, Neu3.1 formed insoluble aggregates that hampered its purification. Neu3.3 oligomers as demonstrated gel filtration chromatography experiments. Actually, first a trimer whereas second pentamer. Intriguingly, despite relevant degree sequence identity similarity, two showed peculiar substrate specificities gangliosides other than GM3, glycoproteins forms sialyllactose. Using molecular modelling crystal structure human cytosolic sialidase NEU2 template, 3D models from zebrafish generated. As expected, typical six blade beta-propeller sialidases, an overall highly conserved active site architecture. The differences among three mainly located loops connecting antiparallel beta strands propeller core. These portions proteins probably responsible for observed specificities, well different subcellular localization aggregation features solution. Finally, silico analysis RNA-Seq data evidenced profile genes during embryogenesis, suggesting roles these development. • Three Neu3 studied various approaches. easily while remains inclusion bodies. self-aggregates paralogs biochemical natural Homology reveal β-strands.