Speed of Kinesin-1 molecular motor

Value 814 nm/sec Range: ±16 nm/sec
Organism Eukaryotes
Reference Schnitzer MJ, Visscher K, Block SM. Force production by single kinesin motors. Nat Cell Biol. 2000 Oct2(10):718-23. p.720 caption to figure 2PubMed ID11025662
Method "Third, the model must describe the behaviour of kinesin as a function of load and ATP concentration. To test this prediction, [investigators] carried out a global analysis of kinesin-velocity data from three Michaelis–Menten curves at different loads and two curves of force against velocity at different ATP concentrations [ref 5] (Fig. 2). The global fit using equations (1) and (4) successfully describes the single molecule velocity over three decades of ATP concentration and up to ~6 pN load. The model generates Michaelis–Menten parameters (Fig. 2a) that are statistically indistinguishable from those obtained previously by fitting to the individual curves [ref 5]. The size of the fitted conformational change parameter, d= 3.7 ±0.3 nm, indicates that kinesin may make its 8-nm step along the microtubule in two ~4-nm stages."
Comments "Figure 2 Global fits of velocity to equations (1) and (4). Solid lines represent fits to velocity data from ref. 5. There were 38 degrees of freedom and 5 independent parameters: d= 3.7±0.3 nm: k0cat= 103±2s^–1: k0b= 1.3±0.1µM^–1s^–1: qcat= 6.2±2.7×10^–3: qb= 4.0±1.4×10^–2. a, Double logarithmic plot of average bead velocity, v, against ATP concentration for various loads (filled circles, 1.05±0.01 pN, n=11–102 runs open circles, 3.59±0.03 pN, n= 8–79 runs diamonds, 5.63±0.06pN, n= 19–58 runs). Vmax= 814±16 nm s^–1, KM= 85±4µM, F= 1.05±0.01 pN: Vmax= 705±17 nm s^–1, KM= 142±7µM,F = 3.59±0.03 pN: Vmax= 383±23 nm S^–1, KM= 310±43µM, F= 5.63±0.06 pN"
Entered by Uri M
ID 105241