title: Purification of a calcium-activated neutral proteinase from human placenta.
abstract: A calcium-activated neutral proteinase has been purified to homogeneity from human placenta. The purified enzyme is a dimer composed of Mr 73 000 and 30 000 subunits. Half-maximal activity is observed at 250 microM Ca2+. It requires reduced sulfhydryl groups and neutral pH for optimal activity. Leupeptin, antipain, E-64, sulfhydryl-blocking agents and endogenous proteinase inhibitor inhibit the purified enzyme. This paper is the first to describe the purification and characterization of a calcium-activated neutral proteinase from a human non-muscular parenchymatous organ.
mesh_terms: D002118:Calcium / Q000494:pharmacology; D002154:Calpain; D010450:Endopeptidases / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D046911:Macromolecular Substances; D008970:Molecular Weight; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy
chemical_list: D046911:Macromolecular Substances; D010450:Endopeptidases; D002154:Calpain; D002118:Calcium