Description
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).