Polyamine Sharing between Tubulin Dimers Favours Microtubule Nucleation and Elongation via Facilitated Diffusion
Figure 12
Influence of spermidine on MAPs-tubulin polymerization.
MAPs-tubulin (12 µM tubulin) was assembled into microtubules as described in materials and methods and then the tubulin content was examined in the supernatant (S) and the pellet (P) after high speed centrifugations. A volume of cold PBS (4°C) equal to that of supernatant was added to pellet. 8 µL of each solution were loaded. The addition of 200 µM spermidine increases the amount of polymerized tubulin even in the presence of MAPs. Furthermore a mixture of taxol and spermidine leads to an additional amount of polymerized tubulin. (M) Molecular weight markers.