Cell-detaching activity mediated by an enzyme(s) obtained from human leukocyte granules

Granule proteins have been isolated from human peripheral blood leukocytes and their effects on intact tissue culture cells have been determined. Three hours after the addition of the mixture of granule hydrolases, both HeLa cells and human newborn fibroblasts were detached from one another and from their growth surface, but they seemed to remain viable, since cell-bound -51Cr was retained. Further studies with HeLa cells indicated that after as long as 24 hours in the presence of these enzymes the cells remained viable as judged by several independent criteria. The enzyme activity responsible for cell detachment was subject to inhibition by various protease inhibitors. Its molecular size, as determined by gel filtration, was approximately 20,000 daltons. In addition, the naturally occurring serum inhibitor of this enzyme activity was characterized as either alpha(1)-antitrypsin or another protein with similar properties.