Purified bovine brain tubulin protein supplied in liquid form at 10 mg/mL in 80 mM PIPES buffer containing 1 mM EGTA, 1 mM GTP, pH 6.8 and 10% glycerol. It is a heterodimer composed of α- and β- tubulin of 55 kDa (molecular weight ≅110 kDa). Polymerization occurs forming microtubules of 25 nm in diameter and average 1650 heterodimers per µm in length. One unit of tubulin is defined as 5.0 mg of purified protein (as determined by the method of Bradford: Bradford, M., Analytical Biochemistry 72, 248, 1976).
|Base Catalog Number||771121|
|Pack Size||1 mg|
|Preparation Method||One unit of tubulin in G-PEM buffer pH 6.8 plus 10% glycerol was incubated at 35°C in a cuvette. The optical density at 340 nm was taken at time intervals. A value of 1.0 OD unit indicates that >97% of the tubulin has polymerized. The polymerization reaction was performed in duplicate.|
|Purity||99% (By SDS-PAGE). Single band at 55 kDa.|
|Specificity||When tubulin at a concentration of 1.0 unit/mL (in G-PEM buffer plus 10% glycerol [v/v]) is incubated at 35°C for 30 minutes an increase in optical density (OD340nm) from 0.0 to 1.0 is observed. This corresponds to a total microtubule (MT) polymer mass of >4.8 mg/mL. The mean length of the microtubule population under these conditions is approximately 10 µm as measured by immunoflourescence microscopy and the average number of MTs per ml is 1.0 x 10<sup>12</sup>.|