What Would Be the Expected Result of a Lys Residue

Multiple Choice

What would be the expected result of a Lys residue being replaced by a Ser residue in the BPG binding site of hemoglobin?

A) BPG would bind tighter because of the loss of a positive charge.
B) BPG would bind tighter because of the gain of a positive charge.
C) BPG would bind less tightly because of the loss of a positive charge
D) BPG would bind less tightly because of the gain of a positive charge.
E) This substitution would have no effect on the binding of BPG.