Periodate oxidation of sea urchin hyalin(s): A glycobiological study towards understanding of hyalin's function as a specific cell adhesion molecule

Abstract

Hyalin (Hy), a set of large glycoproteins containing 2‐3% carbohydrate appears to be a specific cell adhesion molecule in the sea urchin embryo model. Sodium (meta) periodate (PI) can selectively degrade carbohydrate by oxidizing the C‐C bonds between vicinal diols. Untreated Strongylocentrotus purpuratus Hy blocked the adhesion of the tip of the archenteron to the roof of the blastocoel (the specific adhesive interaction under study) in two assays: (1) a microplate assay using live Lytechinus pictus embryos and (2) using dissected pieces of the archenteron and blastocoel roof. Hy cross reacts between these two species. PI treated Hy did not block this interaction in either assay. The microplate analysis, with over 16,000 L. pictus embryos, indicated that 6 hr PI treated Hy (0.17‐0.34 mg treated Hy/ml low calcium artificial sea water ‐LCSW) did not block the cellular interaction, while untreated Hy (0.17‐0.34 mg untreated Hy/ml LCSW) did. 76.4‐77.2% ± 2% of the embryos in PI treated Hy possessed complete archenterons, while 2.7‐7.6% ± 12% possessed complete archenterons in the untreated Hy samples with a p value of less than 0.001. Similar results were obtained using the dissected pieces assay. While this study suggests that Hy carbohydrate is involved in Hy function, further studies are needed to determine if PI is also affecting Hy in other ways (Supported by NIH NIGMS SCORE (S0648680), MARC, RISE, the Joseph Drown Foundation and the Sidney Stern Memorial Trust).