Fig. 2. Dissociation of the /ß tubulin heterodimer by the anti-ß-tubulin antibody. Tubulin heterodimer purified from mouse brain by chromatography on phosphocellulose columns (Tubulin PC) and consisting of equal amounts of - and ß-tubulin was submitted to immunopurification by an anti-ß-tubulin antibody (3F3G2), as described for Fig. 1. The anti-ß-tubulin antibody purified almost exclusively ß-tubulin because it caused dissociation of the heterodimer.