Alterations in sialic-acid O-acetylation glycoforms during murine erythrocyte development

Vinay S. Mahajan; Faisal Alsufyani; Hamid Mattoo; Ian Rosenberg; Shiv Pillai

However, in the setting of a competitive binding assay, the lectin domain of BHE modestly hampered TER-119 binding to its epitope in a dose-dependent manner ( Fig 4C) . Given that both CHE and BHE have evolved as receptor-destroying enzymes that recognize 9-O-acetyl sialic acids, it was not surprising that both CHE-Fc and BHE-Fc pre-treatment of mouse RBCs was able to eliminate the corresponding virolectin receptor binding (Fig 4D) . Although treatment with BHE-Fc completely eliminated CHE-FcD binding, CHE only partially eliminated BHE-S40A-Fc binding (Fig 4D) . These data are consistent with the notion that the BHE virolectin and enzyme has the ability to recognize modified 9-O-acetyl sialic acid ligands that are not recognized by CHE. Since BHE has been shown to bind to 7,9-di-O-acetyl sialic acid while CHE cannot (Langereis et al., 2015; Bakkers et al., 2016) , our results support the notion that 7,9 di-O-acetyl sialic acid is a component of the TER-119 epitope and is expressed in the erythroid lineage from the Ery-A stage onwards.