Fig 5. Higher oligomerization of NS1 is responsible for the membrane association and secretion into the culture supernatants.
(A) The properties of the wild type NS1 and mutant NS1I273H carrying MBP-tag were analyzed by fast protein liquid chromatography (FPLC). (B) The expressions of the wild type NS1 and mutant NS1I273H in each fraction were confirmed by immunoblotting using anti-NS1 antibody. (C) An illustration shows the image of liposome alteration by incubation with NS1. Conversion of liposomes into small heterogeneous lipid particles was examined by the incubation with NS1. The purified wild type NS1 or mutant NS1 (I273H, I273L and F160D) was incubated with the liposomes (composition 1:9 cholesterol:phosphatidylcholine) and visualized by the negative-stain EM. White scale bars represent 500 nm. The dot graph showed the size of liposome incubated with the respective NS1 proteins. Statistical significances were determined by the Kruskal–Wallis test with pairwise comparisons using Tukey-Kramer-Nemenyi all-pairs test with Tukey-Dist approximation. Significantly different values are indicated by asterisks (*).