Tuning proton affinity. The pKa of an acid depends part,y on its environment. Predict the effect of each of the following environmental changes on the pKa of a glutamic acid side change.
(a) A lysine side chain is brought into proximity.
(b) The terminal carboxyl group of the protein is brought into proximity.
(c) The glutamic acid side chain is shifted from the outside of the protein to a nonpolar site inside.