Fig. 1: Kinesin motility in ATP and ATPγS.
From: ATPγS substantially defeats the biasing mechanism for kinesin steps
Microtubule gliding velocity in kinesin surface assays as a function of nucleotide concentration for (a) ATP; (b) ATPγS. Data are fitted with the Michaelis-Menten function: Km [ATP] = 25.7 μM, Vmax [ATP] = 790 nm/s, Km [ATPγS] = 3.1 μM and Vmax [ATPγS] = 12 nm/s. c Effect of the ratio of ATP to ATPγS on microtubule gliding velocity. The x-axis represents the percentage of ATP relative to ATPγS, ranging from 100% ATP (0% ATPγS) to 100% ATPγS, with the corresponding microtubule gliding velocities plotted on the y-axis. Note the ~75% reduction in gliding velocity with the addition of 25% ATPγS. n = 26 (a), n = 31 (b), n = 15 (c). Error bars show ± standard error of the mean (SEM) (d–g) example trapping records. Vertical divisions are at 1 second intervals. Horizontal grid lines are 8 nm apart. Steps marked in green are detected based on their t-score cutoff (see Methods). Step detection was performed using t-score cutoffs of 15 for d–f and 18 for g.
