(A) Comparative aminoacid sequence analysis. Amino acids alignment of the NS4B and N-NS4B/WARF4. Identical residues are shown as dots. The arrow represents the 14 AA target of the anti-NS4B antibody. (B) Western blotting analysis of His-NS4B/His-WARF4 proteins employing MAb 3A12 and the anti-NS4B antibody. The analysis was carried out to demonstrate the different amino acids composition of N-NS4B/WARF4 protein relative to the terminal region of NS4B protein. The first three lanes show the reactivity of the anti-His antibody with the His-tagged proteins used in the same western blotting as positive controls. The anti-NS4B antibody did not react with the His-WARF4 protein (lane 4). Similarly, the MAb 3A12 did not react with His-NS4B protein (lane 9). The His-Envelope protein was used as negative control.