[Ak]

im looking at a past exam for my biochem course and the question says something like:

Asp side chain COOH is involved in electrostatic interaction with side chain of Lys, what happens to the pKa of the Asp side chain?

im thinking it decreases because once the H is removed then there is an electrostatic effect right? before u have +NH2 on lys and neutral COOH but once you remove the H it becomes COO- and +NH2, so pKa decreases

a second questions ask what happens to the side chain if its buried in the core of a protein?

i cant really explain why but i think its because its harder to get to (shielded) so the pKa increases

What do u guys think?