Double and single exponential kinetics of microtubule assembly in vitro.
The kinetics of the microtubule protein assembly were studied in Mes buffer, pH 6.6, at 28 degrees C. The assembly under above conditions follow a kinetic expression containing two exponential terms. The observed two rate constants depend on protein concentration, and are on the order of 10(-2) sec-1 and 10(-3) sec-1. When CaCl2 is added to the system in low concentration, the kinetic expression becomes single exponential. The observed rate constant is independent of protein concentration and its value is 5 X 10(-3) sec-1. It is concluded that the double exponential kinetics correspond to favorable assembly conditions, probably to a high extent of nucleation, whereas the single exponential kinetics correspond to favorable assembly conditions, probably to a high extent of nucleation, whereas the single exponential kinetics is a slower process which occur under hindered assembly conditions.
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D002122:Calcium Chloride / Q000494:pharmacology; D002417:Cattle; D066298:In Vitro Techniques; D007700:Kinetics; D008868:Microtubule Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008954:Models, Biological
D008868:Microtubule Proteins; D002122:Calcium Chloride