title: Phosphorylation of the red blood cell membrane during the active transport of C++.
abstract: The phosphorylation of red blood cell membrane fragments (RBCMF) during Ca++ transport was investigated. When red cell membrane fragments are incubated with [gamma-32P]ATP under the experimental condition which minimizes the phosphorylation of Na+-K+-ATPase, RBCMF are labeled in the presence of Mg++ without Ca++. When Ca++ is added, the labeling decreases due to dephosphorylation of RBCMF. The initial reaction of phosphorylation is reversed in the presence of excess ADP. The treatment of RBCMF with n-ethylmaleimide (NEM) does not interfere with the initial phosphorylation reaction, but blocks the dephosphorylation in the presence of Ca++. These data suggest that the enzymatic sequence of the Ca++ transport mechanism may be very similar to that of the Na+ transport mechanism.
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D002118:Calcium / Q000097:blood* / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004912:Erythrocytes / Q000201:enzymology / Q000378:metabolism*; D005033:Ethylmaleimide / Q000494:pharmacology; D006461:Hemolysis; D006801:Humans; D008274:Magnesium / Q000494:pharmacology; D010710:Phosphates / Q000097:blood*
chemical_list: D010710:Phosphates; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D004492:Edetic Acid; D000251:Adenosine Triphosphatases; D008274:Magnesium; D005033:Ethylmaleimide; D002118:Calcium