Isolation of a low molecular weight antibacterial system from human amniotic fluid

Abstract

A low molecular weight antibacterial system has been isolated from human amniotic fluid. The bacterial inhibitor requires the metal cation zinc and a peptide with a molecular weight of 630. The peptide component was purified using ultrafiltration, gel filtration, and ion exchange chromatography. It can be inactivated by digestion with carboxypeptidase. The amino acid composition of the peptide is: 3 glutamine glutamic acid, 2 glycine, and 1 lysine. Removal of zinc from the peptide has been shown to remove bacterial inhibitory activity.