Reactivation of digoxigenin and digoxigenin n-digitoxide-inhibited enzyme with 150 mm NaCl at pH 7.5. Panels A and B are enzymes phosphorylated by MgPi, and in the E2-P ground state stabilized by BeFx, respectively. The symbols are: ♢, digoxigenin; ○, digoxigenin monodigitoxide; □, digoxigenin didigitoxide; ▿, digoxigenin tridigitoxide (digoxin); ▵, digoxigenin tetradigitoxide.