title: Antibacterial activity in human amniotic fluid: dependence on divalent cations.
abstract: Antibacterial activity, tested against Bacillus subtilis, was present in all 34 samples of human amniotic fluid collected between 37 and 41 weeks gestation. High-molecular-weight (beta-lysin) antibacterial activity was reduced after treatment with ethylene diamine tetra-acetic acid (EDTA), but not after treatment with 1, 10-phenanthroline or diphenylthiocarbazone. The activity was restored following incubation with magnesium, calcium, or zinc. Low-molecular-weight antibacterial activity (less than 1000 daltons) in acid-alcohol extracts was reduced after treatment with dithizone, but not after treatment with EDTA or 1, 10 phenanthroline. Activity was restored after treatment with manganese, cobalt or zinc. High-molecular-weight (beta-lysin) activity was therefore biochemically similar to serum beta-lysin but biochemically different from the low-molecular-weight antibacterial component of amniotic fluid.
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000502:physiology*; D023181:Antimicrobial Cationic Peptides; D001412:Bacillus subtilis / Q000187:drug effects / Q000254:growth & development*; D001798:Blood Proteins; D002413:Cations, Divalent / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D005260:Female; D006801:Humans; D008970:Molecular Weight; D011506:Proteins / Q000037:antagonists & inhibitors / Q000502:physiology; D014462:Ultrafiltration
chemical_list: D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D002413:Cations, Divalent; D002614:Chelating Agents; D011506:Proteins; C011679:beta lysin, human