NORMAL IMMUNOSUPPRESSIVE PROTEIN - ISOLATION OF A GLYCOPROTEIN ACTIVE FRACTION

  • 1 January 1980
    • journal article
    • research article
    • Vol. 39  (3) , 305-309
Abstract
Experiments to determine the nature of the active moiety of normal immunosuppressive protein (Nip) were performed using Sepharose Con [concanavalin] A fractionation. Nip was a glycoprotein or a glycopeptide. The fraction eluted by 0.2 M mannose was as active as the crude Nip preparation in inhibiting [mouse lymphoma] EL4 tumor cell proliferation in vitro. It also gave a positive hemagglutination inhibition test when added to a rabbit anti-Nip antibody system. The resistance of Nip to boiling as well as the positive PAS [periodic acid-Schiff] staining also confirmed the glycoprotein or glycopeptide nature of Nip.