title: 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.
mesh_terms: D000653:Amniotic Fluid / Q000382:microbiology*; D002268:Carboxypeptidases / Q000494:pharmacology; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003470:Culture Media; D004230:Dithizone / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000254:growth & development*; D006801:Humans; D008970:Molecular Weight; D014462:Ultrafiltration; D015032:Zinc / Q000494:pharmacology
chemical_list: D003470:Culture Media; D004230:Dithizone; D002268:Carboxypeptidases; D015032:Zinc