Microtubule formation from two components separated by gel filtration of a tubulin preparation

摘要: Abstract 1. (1) A tubulin preparation, purified by two cycles of polymerisation in 4 M glycerol, was further fractionated into components chromatography on a column 6% agarose. One fraction pure dimer devoid any contamination high molecular weight ingredients (component T). The other an aggregate containing several minor N). 2. (2) Microtubulue formation from these followed quantitative way measuring flow birefringence ( Δn ). When component N incubated at 37° C, instantaneous increase observed even low concentration protein, and the extent roughly proportional to protein concentration. With T, occurred after lag period, only higher than least 0.5 mg/ml. Polymerisation T greatly accelerated when small amount added reaction medium. 3. (3) Component dissociated ionic strength medium increased. On reducing strength, reassociated form aggregate, which again capable accelerating T. Minor contained were not completely removed during course its dissociation reassociation. dynein-like that present N, however, longer detectable aggregate.