5-lipoxygenase from rat PMN lysate.

The products of arachidonic acid metabolism in the 15,000xg supernatant of sonicated rat PMN are described. Only products derived from 5-lipoxygenase are observed. These products are 5-HETE and products derived from hydrolysis of LTA4, particularly LTB4. Some minor products derived from decomposition of 5-HPETE are also observed. The dependence of the activity of 5-lipoxygenase on enzyme and on substrate concentrations is presented and discussed in terms of a kinetic model that includes enzyme inactivation during turnover and substrate inhibition. The 5-lipoxygenase activity is stimulated by Ca++ and ATP.