by using various methods to fractionate the microtubule preparation into subfractions ( e.g. , phosphocellulose chromatography to obtain purified 6s tubulin and soluble microtubule-associated proteins , and gel exclusion chromatography on bio-gel a-150m to obtain 10-nm filaments ) , we found that all the fractions exhibited some enzymic activity , but that most of the phosphodiesterase activity was localized in the 10-nm filament fraction .
C0026046
microtubule
C0041348
tubulin