Membrane site modified on induction of the transformation of lymphocytes by periodate

Lymphocytes isolated from different sources undergo blastogenesis after mild treatment with periodate. Incubation of mouse spleen lymphocytes with neuraminidase or papain markedly reduces their response to periodate. Transformation induced by concanavalin A of the enzymically treated cells is not impaired. Blastogenesis induced by periodate is decreased when periodate-treated lymphocytes are reacted with borohydride, hydroxylamine, or semicarbazide. Treatment with these compounds does not affect transformation of cells by concanavalin A. It is suggested that different membrane sites are involved in lymphocyte transformation induced by periodate and by concanavalin A. The periodate target site seems to include a glycoprotein complex containing sialic acid that yields, on oxidation, an aldehyde moiety that is essential for transformation.