Figure 3
From: Identification of critical residues of influenza neuraminidase in viral particle release
Molecular analysis of amino acid region 226-301 in NA function. A, schematic of NAC (NAA 226-301). NAH sequence is colored red and NAA sequence is colored yellow. Single and combined substitutions generated in NAC (NAA 226-301) are shaded. B, relative infectivity of 293T and A549 target cells challenged with pseudovirus produced in the presence of respective NAC (NAA 226-301) mutants. Luciferase activity is presented as fold-change. Experiments were performed in triplicates and repeated several times, and error bars indicate standard deviations. C, hemagglutination activity of NAC (NAA 226-301) substitution panel. Pseudovirions were mixed with chicken red blood cells and HA titers recorded. D, neuraminidase activity of NAC (NAA 226-301) substitution mutants measured by the release of fluorogenic substrate 4-MUNANA. Experiments were performed in triplicates and repeated several times, and error bars indicate standard deviations.