Use of specific glycosidases to probe cellular interactions in the sea urchin embryo

Abstract

We present an unusual and novel model for initial investigations of a putative role for specifically conformed glycans in cellular interactions. We have used α-and ß-amylase and α-and ß-glucosidase in dose-response experiments evaluating their effects on archenteron organization using the NIH designated sea urchin embryo model. In quantitative dose-response experiments, we show that defined activity levels of α-glucosidase and ß-amylase inhibited archenteron organization in living Lytechinus pictus gastrula embryos, whereas all concentrations of ß-glucosidase and α-amylase were without substantial effects on development. Product inhibition studies suggested that the enzymes were acting by their specific glycosidase activities and polyacrylamide gel electrophoresis suggested that there was no detectable protease contamination in the active enzyme samples. The results provide evidence for a role of glycans in sea urchin embryo cellular interactions with special reference to the possible structural conformation of these glycans based on the differential activities of the α-and ß-glycosidases.

A role for polyglucans in a model sea urchin embryo cellular interaction

“…This laboratory has been studying this cellular interaction for many years (Latham et al ., 1999; Khurrum et al ., 2004; Razinia et al ., 2007; Carroll Jr et al ., 2008; Ghazarian et al ., 2009; Idoni et al ., 2010). Recent work from our laboratory has shown that specific glycosidases added to whole developing embryos inhibit archenteron organization and development (Idoni et al ., 2010). This previous work utilized a microplate assay that could not be used to identify the site of action of glycosidases because of the complexities associated with work in whole, living embryos (Idoni et al ., 2010).…”

“…Recent work from our laboratory has shown that specific glycosidases added to whole developing embryos inhibit archenteron organization and development (Idoni et al ., 2010). This previous work utilized a microplate assay that could not be used to identify the site of action of glycosidases because of the complexities associated with work in whole, living embryos (Idoni et al ., 2010). In the study reported here the archenteron and blastocoel roof were microdissected out of intact, formaldehyde-fixed embryos (Coyle-Thompson & Oppenheimer, 2005).…”

Simple Novel Assays in Glycobiology

“…Because of its transparency and simplicity, the sea urchin is well suited for research in glycobiology. We have developed new assays using the sea urchin embryo to learn about the roles of specific glycans in mediating cellular interactions [2][3][4][5]. The first assay involves culturing sea urchin embryos in 96 well microplates with and without glycans or glycosidases over time and counting the different morphologies of the developing gut (archenteron) in tens of thousands of living embryos [2,4].…”

Covid-19 Pandemic, Glycobiology, Glycan Shields, Vaccine Strategies, Heparin Sulfate: A Mini Review

“…This laboratory has studied the role of carbohydrates in embryonic development and cancer for a half century [1][2][3][4][5][6][7][8].…”

“…The author of this current work, Steve Oppenheimer, has been recognized by election as Fellow of the American Association for the Advancement of Science (AAAS) primarily for his work in the field of glycobiology. Studies beginning at Johns Hopkins [1] have identified metabolic pathways and specific glycans involved in cellular interactions in the developing sea urchin embryo model [2][3][4][5][6][7] and in cancer cells [1]. A heavily downloaded review was published by this group that covered the fundamentals of glycobiology [8].…”