Fig. 2. Expression of surface tTG induces the binding of 42 kDa Fn fragment and Fn to cells. (A) Analysis of binding of [¹²⁵I]42 kDa fragment to vector, tTG[2] and tTG_C277S[2] transfectants in suspension. (B) Anti-tTG antibody suppresses the binding of [¹²⁵I]42 kDa fragment to tTG[2] transfectants in suspension. (C) Binding of [¹²⁵I]Fn to vector and tTG[2] transfectants in suspension. (D) The lack of binding of [¹²⁵I]42 kDa fragment to monolayers of vector, tTG[2] and tTG_C277S[2] transfectants. Adherent cells plated for 2 or 72 hours were analyzed for binding [¹²⁵I]42 kDa fragment. (B,C) Where indicated, 20 µg/ml anti-tTG antibody, blocking anti-5ß1 integrin mAb BMA5, control nonimmune IgG or 5 µM unlabeled 42 kDa fragment was used during incubation of cells with ¹²⁵I-labeled proteins. Nonspecific binding in the presence of excess unlabeled 42 kDa fragment was subtracted. The results are representative of three independent experiments (mean±s.e.m.).