Fig. 3.

Recombinant 4F/4R (amino acid position 482-678), 6F/6R (830-1071), and Mod4F/Epi4R (476-520) spike (S) proteins of turkey coronavirus (TCoV) expressed in E. coli and purified on His columns can be recognized by anti-TCoV serum in a western blot assay. (a) Recombinant 6F/6R and 4F/4R S proteins transferred from a 12.5% glycine SDS-PAGE gel to a nitrocellulose membrane were stained with 1:400-diluted anti-TCoV serum, followed by 1:400-diluted horseradish peroxidase (HRP)-conjugated goat anti-turkey IgG (H+L) secondary antibodies. The arrows point to 6F/6R S protein at 31 kD and 4F/4R S protein at 26 kD. (b) Recombinant Mod4F/Epi4R S protein transferred from a 16%/6 M urea Tricine SDS-PAGE gel to a nitrocellulose membrane was stained with 1:400-diluted anti-TCoV serum, followed by 1:400 HRP-conjugated goat anti-turkey IgG (H+L) secondary antibodies. The arrow points to a dimer of Mod4F/Epi4R S protein at 10 kD