Isolation of microtubules by assembly/disassembly methods

Area of Science:

• * Cell Biology
• * Biochemistry

Background:

• * Microtubules are dynamic polymers essential for cellular functions.
• * Tubulin dimer-polymer equilibrium governs microtubule assembly and disassembly.
• * Microtubule-associated proteins (MAPs) influence microtubule stability and dynamics.

Purpose of the Study:

• * To describe optimized procedures for isolating microtubules in vitro.
• * To present methods for controlling tubulin assembly and disassembly using temperature.
• * To evaluate the impact of glycerol on microtubule yield and MAP association.

Main Methods:

• * Microtubule isolation via cycles of temperature-induced assembly and disassembly.
• * Polymer collection by centrifugation.
• * Use of buffers with and without glycerol to modulate assembly.
• * Application to various vertebrate brain tissues and non-neuronal tissues.

Main Results:

• * Temperature control allows for repeated in vitro microtubule assembly and disassembly cycles.
• * Glycerol inclusion increases tubulin yield by disrupting hydration shells.
• * Glycerol slightly decreases the ratio of MAPs to tubulin due to reduced binding.
• * Two distinct isolation protocols are presented, with specific tissue recommendations.

Conclusions:

• * Optimized temperature-cycling procedures enable efficient in vitro microtubule isolation.
• * Glycerol-containing buffers enhance tubulin yield, particularly for tissues with lower tubulin concentration.
• * The choice of protocol depends on the tissue source and desired MAP-to-tubulin ratio.