Microtubular proteins

This chapter discusses microtubular proteins. Tubulin is a heterogeneous protein and this heterogeneity manifests at two levels. The dimer are composed of similar evolutionarily divergent polypeptide chains, and exists in a number of forms within an organism that distinguished genetically or by post­translational modification, giving rise to a number of “isozymic” tubulins. The methodological approach facilitated the study of the molecular biology. The use of drugs, providing functional and mechanistic insight, and in vitro polymerization techniques has been instrumental in the elucidation of the mechanism of assembly, disassembly, and electrophoretic techniques. Polyacrylamide gel electrophoresis (PAGE) techniques have played a major role in the identification and biochemical characterization of the tubulins and associated proteins. Many important chemical and functional questions remain open, such as the significance of multiple tubulins and the mechanisms of flagellar motility.