Calcium-activated ATPase of the human placenta: identification, characterization, and functional involvement in calcium transport.
A specific, membrane-bound, Ca2+-activated and Mg2+-dependent adenosine triphosphatase (ATPase) activity is present in the human term placenta. The enzyme activity is fractionated electrophoretically into two distinct forms which correspond to molecular weights of 120,000 and 145,000. Cytohistochemistry localized the Ca2+-ATPase to the chorionic villi of the placental labyrinth, and specific staining was primarily associated with the syncytio- and cytotrophoblast layers as well as the perivascular cells. The enzyme activity is inhibited by phenothiazin and erythrosin B which also significantly inhibit active calcium in vitro by placental microsomal membrane vesicles.
D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy
D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases; D002118:Calcium