Figure 3.

MT assembly in bovine brain extract (A) and decoration of MTs by endogenous proteins (B). The cell-free extract concentration was 20 mg/ml with roughly 15% tubulin content. The polymerization was initiated at 37°C by addition of 20 μM taxol in buffer B. Inset shows the immunoblot data using anti-TPI antibody raised against rabbit muscle TPI. T, S, and P are samples from total, supernatant, and pellet phases, respectively; 1, 2, 3, and 4 are controls using 600, 300, 150, and 75 ng of isolated TPI, respectively. Electron microscopic image was prepared as described in Materials and Methods.