Study of the 10-nm-filament fraction isolated during the standard microtubule preparation.

The cold non-depolymerizable fractions obtained during the standard procedure for the isolation of microtubules from ox brain stem-cerebral hemispheres and spinal cord have been studied. The cerebral-hemisphere preparation was composed of 10-nm filaments but also contained large amounts of membranes. The polypeptide content included tubulin, microtubule-associated proteins and minor proteins corresponding to the neurofilament triplet of proteins of mol.

[Preparation of highly purified microbules and evidence for a novel molecular arrangement at low temperatures].

Microtubules were prepared by in vitro polymerization-depolymerization cycles, 1.0 M NaCl which totally depolymerizes was then added to the preparation. After removal of NaCl new arrangements of tubulin were observed at 4 degrees C: simple and double rings as well as fibrils.