AZUROCIDIN, A NATURAL ANTIBIOTIC FROM HUMAN NEUTROPHILS - EXPRESSION,ANTIMICROBIAL ACTIVITY, AND SECRETION

The azurophil granules of human PMN contain four antibiotic proteins, the serprocidins, which have extensive homology to one another and to serine proteases. Azurocidin, a member of this family, is a 29-kDa gly coprotein with broad spectrum antimicrobial activity and chemotactic a ctivity toward monocytes. Insect cells transfected with a baculovirus vector carrying azurocidin cDNA produced a recombinant azurocidin prot ein. We purified the recombinant azurocidin protein from the culture m edium of the infected cells and showed that it retained the antimicrob ial activity of the native neutrophil-derived molecule. In addition, w e present evidence that a 49-amino-acid region of the recombinant azur ocidin protein is required for its secretion from insect cells. (C) 19 96 Academic Press, Inc.