Scaling of microtubule force-velocity curves obtained at different tubulin concentrations.
We present a single curve that describes the decay in average growth velocity for microtubules in response to a mechanical force. Curves obtained at two new and one previously studied tubulin concentrations coalesce when normalized with the growth velocity at zero load. This scaling provides direct evidence for a force-independent molecular off rate, in agreement with Brownian ratchet models. In addition, microtubule length changes were measured with a precision up to 10 nm, revealing that microtubules under load abruptly switch between different growth velocities.
Janson
Marcel E
ME
FOM Institute AMOLF, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
Dogterom
Marileen
M
D019281:Dimerization; D008870:Microtubules / Q000737:chemistry*; D008954:Models, Biological; D020409:Molecular Motor Proteins / Q000737:chemistry; D014404:Tubulin / Q000737:chemistry*
D020409:Molecular Motor Proteins; D014404:Tubulin