Sandbox Reserved 1846: Difference between revisions

<scene name='10/1075247/F243_original/1'>Phe243</scene> is located 3.6 Å from the ligand, <scene name='10/1075247/Original_15_mutation_structure/6'>Reference Phe243</scene>. Two mutations at this position, <scene name='10/1075247/F243i/1'>F243I</scene> and F243W, increase the catalytic activity of the enzyme. The larger tryptophan at position 243 stabilizes the ligand through stronger hydrophobic and π–π interactions, pulling it closer to the catalytic site despite its size. The F243I mutation inserts the smaller isoleucine whose side chain allows the ligand to sit closer. This reduces the ligand distance to 3.0 Å, improving substrate binding. The F243W mutation inserts the bulkier, nitrogen-containing aromatic aide chain. Trp brings the ligand slightly closer at 3.2 Å and introduces potential for new interactions, such as hydrogen bonding or [https://en.wikipedia.org/wiki/Pi-stacking#:~:text=In%20chemistry%2C%20pi%20stacking%20(also,interaction%22)%20is%20electrostatically%20repulsive. π-stacking]. Both mutations result in improved catalytic performance. The F243I mutant shows a 27.5% increase in activity, while the F243W mutant shows a 17.5% increase, compared to the wild-type enzyme.<ref name="Tournier"/>