Oxyanion Hole

Memory Hack💡

Notes

The oxyanion hole is a specialized pocket within the enzyme that stabilizes the negative charge that develops on the oxygen atom during the reaction.

But what does "stabilization" actually mean?

Think of the oxyanion hole as a small supportive pocket that temporarily holds and stabilizes the negatively charged oxygen during the tetrahedral intermediate stage. At this point, the oxygen is in an energetically unfavorable state and would normally be too unstable to persist long enough for the reaction to proceed.

By providing stabilizing interactions, the oxyanion hole lowers the energy of the tetrahedral intermediate, making its formation possible. Without this stabilization, the intermediate would be too unstable to form efficiently, and the reaction would be much less favorable.

The video below goes over the entire mechanism, but references the oxyanion hole for your review.