FIG 4.

Expression and tissue binding specificities of S1 proteins. (A) Recombinantly expressed S1 domains of chicken IBV-M41 (IBV S1), turkey coronavirus (TCoV S1), guineafowl coronavirus (GfCoV S1), and quail coronavirus (QCoV S1) were analyzed by SDS-PAGE and Western blotting. (B) Enteric CoV S1 proteins were applied onto respiratory and intestinal tissues of their respective hosts. S1 was applied onto both sialylated (−NA) and desialylated (+NA) tissues. (C) IBV S1 was applied onto sialylated (−NA) and desialylated (+NA) chicken tracheas as a control. Desialylation was performed by treating tissues with bacterial neuraminidase (NA), as described in Materials and Methods. Results are representative of data from three independent experiments.