Methods for the Neurochemical Study of Microtubules

Abstract

The microtubule and its protein subunit tubulin are found widely distributed in plant and animal cells, and there appears to be nothing unique about the morphology or chemistry of these entities in brain. The unusual aspect of their occurrence in nervous tissue is their high concentration. Microtubules are seen in great numbers on electron microscopic examination of neurons. Tubulin concentrations in brain have been reported between 11% and over 40% of the total soluble protein of brain (Dutton and Barondes, 1969; Feit et al., 1971a). These exceptionally high tubulin concentrations have been one of the most significant factors in convincing neurochemists that microtubules must play an important functional role in nervous tissue. The actual physiological role of the microtubule is unknown, although it has been implicated in both axoplasmic flow and neurosecretion. In this chapter, some useful techniques for the manipulation, purification, and identification of tubulin will be discussed. In the interests of brevity, only a portion of the techniques which have been used will be covered, although it is hoped that the selection maintains the most useful and general procedures.