Demonstration of calcium-dependent chemotactic factor activatable esterase activity in human neutrophils:...

An increase in esterolytic activity, as measured by [3H] BAEE hydrolysis, was demonstrated in human neutrophil suspensions following incubation with three distinct chemotactic factors. The increased activity was demonstrated in intact cells as well as in cell lysates. The FMLP-enhanced enzymatic hydrolysis of BAEE was found to be calcium dependent. Esterase activation by FMLP was maximal at 1.0 mM of added calcium. Similar dose-response curves for esterase activation, chemotaxis, and chemotactic deactivation were obtained with the chemotactic factor FMLP, suggesting that in human neutrophils all three functions utilize some of the same early molecular events following chemotactic factor binding to th neutrophil surface.