Identity and Origin of the ATPase activity associated with neuronal microtubules. I. The ATPase activity is associated with membrane vesicles.

Abstract

Microtubule protein purified from [hog] brain tissue by cycles of in vitro assembly-disassembly contains ATPase activity that was postulated to be associated with microtubule-associated proteins (MAP) and therefore significant for studies on microtubule-dependent motility. Of the ATPase activity > 90% is particulate in nature and may be derived from contaminating membrane vesicles. The MAP (MAP-1, MAP-2 and tau factors) and other high MW polypeptides do not contain significant amounts of ATPase activity. These findings do not support the concept of brain dynein or of MAP with ATPase activity.