At the active site of Chymotrypsin, there are a critical residue Aspartic acid102 that is negatively charge that stabilize the positively charged-protonated Histidine57. If the Asp102 is mutated to Asparagine102, can it still stabilize the +His57?

I said yes it could due to the lone pairs of electrons on the oxygen on Asparagine102 that would be attracted to the +His57. Would you agree?

Question

At the active site of Chymotrypsin, there are a critical residue Aspartic acid102 that is negatively charge that stabilize the positively charged-protonated Histidine57. If the Asp102 is mutated to Asparagine102, can it still stabilize the +His57?

I said yes it could due to the lone pairs of electrons on the oxygen on Asparagine102 that would be attracted to the +His57. Would you agree?

preetha · Answer

I would probably say no.  The Asparagine has N which is an electron donor.  So you have changed the polarity of the active site. The COO- is very different to the C=O NH2 amide group.

ookawaiioo · Answer

The answer was yes it can due to the hydrogen bond from lone pairs on the O=C to the +His57...... Man I should have known this! Im so disappointed in myself!