Abstract: | The oxygen isotope exchange reactions catalyzed by sea urchin Strongylocentrotus intermedius spermatozoa dynein I were studied with a view of comparing molecular mechanisms of ATP hydrolysis by dynein and myosin ATPases. It was demonstrated that the isotope exchange takes place during ATP hydrolysis and during enzyme incubation with ADP and Pi and is absent when the enzyme is incubated with Pi. It was assumed that the molecular mechanisms of ATP hydrolysis by dynein I and myosin are identical. |