The iron-binding site of transferrin in Figure 19-15 accommodates certain other metal ions besides Fe3 and cer- tain other anions besides coj-. Data are given in the table for the titration of transferrin (3.57 mg in 2.00 mL) with 6.64 mM GaH in the presence of the anion oxalate, C20~-, and in the absence of a suitable anion. Prepare a graph similar to Fig- ure 19-16, showing both sets of data. Mark the theoretical equivalence point for binding two Ga3 ions per molecule of protein. How many Ga3 ions are bound to transferrin in the presence and absence of oxalate?