Weidekamm E, Brdiczda D
Biochim Biophys Acta. 1975 Aug 5;401(1):51-8. doi: 10.1016/0005-2736(75)90340-5.
(1) A water soluble (Ca2+ plus Mg2+)-activated APTase has been extracted with 0.1 mM EDTA and 0.1 mM ATP from human erythrocyte membranes. (2) The specific activity of the extracted protein is increased 4- to 6-fold in comparison with untreated ghosts. (3) Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of [gamma-32P]ATP-labeled erythrocyte membranes shows that the (Ca2+ plus Mg2+)-activated ATPase is located in the "spectrin" region (Mr 220 000-240 000). The radioactivity of these high molecular peptide bands is decreased markedly after the extraction of the ATPase at low ionic strength.
