digoxigenin-3,12-dibromoacetate ( ddb ) , an alkylating derivation of digoxigenin , was synthesized and tested as a cardiotonic steroid ( cs ) site directed affinity label for na+ +k+ -atpase ( atp phosphohydrolase ec 3.6.1.3 ) .
C0001479
na
C0001473
atp phosphohydrolase