FIG 6.

M2 protein is a homo-oligomer. SDS-PAGE of 7.5 μg of purified recombinant M2 was performed under nonreducing conditions (0 mM dithiothreitol [DTT]; first lane after the molecular weight [MW] ladder) and in the presence of increasing amounts of reducing agent (DTT) from 1 mM to 16 mM, loaded, respectively, from lanes 2 to 6. The seventh lane corresponds to the protein completely reduced by beta-mercaptoethanol. Detection was performed with Coomassie blue staining. Each arrow corresponds to the position of an intermediate product of the oligomerization. Each number indicates the putative number of protomer in the visualized band.