The Immobilization Antigens of Tetrahymena thermophila Are Glycoproteins

Abstract
The four immobilization antigens controlled by the SerH locus in Tetrahymena thermophila have been isolated and partially characterized (Doerder, F. P. & Berkowitz, M. S. 1986. Purification and partial characterization of the H immobilization antigens of Tetrahymena thermophila. J. Protozool., 33:204–208). We show here, using immunoprecipitation and electrophoresis after labeling with 35S‐methionine, 14C‐mannose, 14C‐glucosamine, and N‐Acetyl‐d‐[1‐3H]glucosamine, that these proteins are glycosylated. We suggest the immobilization antigens in Tetrahymena may be anchored to the surface membrane by phosphatidylinositol glycans.