title: Absence of one component of spectrin adenosine triphosphatase in hereditary spherocytosis.
abstract: The stimulation by calcium and magnesium of ATPase activity of isolated ghosts, of water-soluble protein (spectrin), and of residual vesicles, derived from normal erythrocytes and from hereditary spherocytes (H.S.), has been measured. The ATPase activity found in normal water-soluble protein (WSP) at low levels of calcium (0.1-2.0 mM) is essentially absent in H.S. water-soluble protein, but the ATPase activity with magnesium and with high levels of calcium (60-100 mM) is the same in H.S. and normal WSP. Compared to normal, H.S. ghosts have increased Mg2+-stimulated activity. This increased activity is retained by the sedimentable vesicles ("residue") after extraction of the ghosts with 0.025 mM EDTA. The Ca2+, Mg2+-ATPase associated with the calcium pump is not significantly different in H.S.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001798:Blood Proteins; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000201:enzymology; D006801:Humans; D008274:Magnesium / Q000494:pharmacology; D013103:Spherocytosis, Hereditary / Q000201:enzymology*; D013156:Splenectomy
chemical_list: D001798:Blood Proteins; D002413:Cations, Divalent; D000251:Adenosine Triphosphatases; D008274:Magnesium; D002118:Calcium