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18-27. The iron-binding site of transferrin in Figure 18-8 can accommodate certain other metal ions besides Fe and certain other anions besidesData are given in the table for the titration of transferrin ( 3.57 mg in 2.00 mL ) with 6.64 mM Ga3+solution in the presence of the anion oxalate, C2O42-, and in the absence of a suitable anion. Prepare a graph similar to Figure 18-11, showing both sets of data. Indicate the theoretical equivalence point for the binding of one and two Ga3+ions per molecule of protein and the observed end point. How many Ga3+ions are bound to transferrin in the presence and in the absence of oxalate?

Short Answer

Expert verified

TheGa3+ ions that are bound to transferrin in the absence of oxalate is zero because the slope does not change

Step by step solution

01

Find Ga3+ ions are bound to transferrin in the presence and in the absence of oxalate

The theoretical equivalence point is:

2,ntransferrincGa3+2molGa/moltransferrin.0.00357gtransferrin81000gtransferrin/moltransferrin=13.3μ³¢

The observed end point is the intersection of lines from first 6 points and last 4 points in the following

The observed end point is 12.2μ³¢the Ga3+ions that are bound to transferrin in the presence of oxalate is:

12.213.3=91.73%

TheGa3+ions that are bound to transferrin in the absence of oxalate is zero because the slope does not change.

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