in the case of microtubule formation , the linkage free energy provided by taxol binding is approximately -3.0 kcal/mol of alpha-beta-tubulin dimer , whereas this quantity is reduced to approximately -0.5 kcal/mol in tubulin-colchicine , indicating the expenditure of much more binding free energy in the latter case for overcoming unfavorable factors , such as steric hindrance and geometric strain .
C0026046
microtubule
C0041348
tubulin