Dispersion of epinephrine sensitive and insensitive adenylate cyclase from the ciliate Tetrahymena pyriformis.

The membrane bound adenylate cyclase (ATP pyrophosphate-lyase (cyclizing) EC 4.6.1.1) of the ciliate Tetrahymena pyriformis could be extracted by washing the membrane fraction with 0.25 M sucrose. The enzyme dissociated in this way did not sediment after centrifugation at 105 000 times g for 2 h and was still responsive to stimulation by epinephrine. Dispersion of the membranes with Triton-X 100 led to purified preparation of the cyclase, which was no longer stimulated by epinephrine but retained fully the activation by fluoride and serotonin.