Turbidimetric studies on microtubule sliding using the stopped-flow-light-scattering method

The turbidity of axonemes during active sliding of microtubules was analysed using the stopped-flow-light-scattering method with high time resolution. Flagella of sea-urchin spermatozoa were demembranated and used after a brief treatment with trypsin. The turbidity of the suspension of flagellar axonemes during ATP-induced disintegration was measured and its time course fitted to a single exponential function which yielded the rate of disintegration, R(1/sec). R coincided well with the velocity of microtubule sliding, V(microM sec) as determined by cinematomicrographic analysis, i.e., R = 0.22 X V, r = 0.9973. It indicates that turbidimetry is a useful method with which to learn the sliding velocity of microtubules. From the dependency of R on temperature, Q10 of the sliding velocity was estimated to be 2.0-2.3 at 43-820 microM of MgATP.