FIG. 4.
Binding of tubulin to monomeric and oligomeric VP40. (A) SDS-PAGE analysis of monomeric and oligomeric His-tagged Ebola VP4031-326. Monomeric His-tagged Ebola VP4031-326 (lane 1) was incubated with 2 M urea and an excess of E. coli nucleic acids to form oligomers (lane 2) and isolated by sizing chromatography. (B) Two micrograms of His-tagged monomeric or oligomeric VP40 was bound to Ni2+ plates and, after blocking, incubated with the indicated amounts of purified tubulin. Plates were washed, and bound tubulin was detected with an anti-tubulin MAb, HRP-conjugated anti-mouse antibody, and chromogenic reagents.