following attainment of a steady state in microtubule mass at 20 degrees c , the rate of incorporation of [ 3h ] gtp ( i.e. , tubulin dimers ) during pulses of constant duration decreased asymptotically toward a constant , nonzero value as the interval prior to label addition to the microtubule solution increased .
C0041348
tubulin
C0026046
microtubule