Figure 7.

Summary of the ligands at the metal coordination sites of sCD39 during the catalytic reaction. The types of groups shown as equatorial ligands were derived from the best fits of ⁵¹V hyperfine values from Table 2. a. The metal ligands in the presence of ADPNP (Species T) represent the conformation of ATP at the beginning of hydrolysis by sCD39. b. The metal coordination sites in the presence of AMPCP (Species D2) show the arrangement of the catalytic site prior to release of ADP as an intermediate product. c. The metal coordination sites in the presence of AMPCP (Species D1) show the conformation of the catalytic site ready to hydrolyze ADP. d. Metal coordination in the absence of nucleotide (Species V) showing the occupancy of the active site by free metal with exclusion of nucleotide and consequent inhibition of sCD39.