Phospholipase A activity associated with membranes of human polymorphonuclear leucocytes.

ABSTRACT: Homogenates of human polymorphonuclear leucocytes (granulocytes) contain a Ca2+-dependent phospholipase A with optimal activity pH7.0. This enzyme is membrane-bound and is enriched in crude cytoplasmic-granule fraction. Ratezonal centrifugation of the cytoplasmic-granule fraction demonstrates that the phospholipase A is associated not only with specific- and azurophilic-granule populations but also with an 'empty' vesicular fraction containing 85% of the total alkaline phosphatase activity of whole homogenate. Thus this phospholipase is associated with granule as well as with other cellular membranes of human granulocytes.

SUBMITTER: Franson R 

PROVIDER: S-EPMC1183734 | biostudies-other | 1977 Dec

REPOSITORIES: biostudies-other