Purification and characterization of a lipocortin-like 33 kDa protein from guinea pig neutrophils.

A lipocortin-like, phospholipase A2 inhibitory 33 kDa protein was purified from guinea pig neutrophils. From amino acid composition and sequence data, this protein was found to have a high degree of homology to human lipocortin I. This protein inhibited porcine pancreatic phospholipase A2 activity in the presence of [3H]oleic acid-labeled Escherichia coli membranes as substrate. Maximal inhibition amounted to 65% whereas 50% inhibition occurred at 83.5 nM. This protein showed F-actin-binding ability in a Ca2+-dependent manner.