Sandbox Reserved 1845: Difference between revisions
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=== Phe243 === | === Phe243 === | ||
<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 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"/> | <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 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"/> | ||
=== Tyr 127 === | === Tyr 127 === | ||
The mutation of Tyr to Gly at <scene name='10/1075247/Y127/4'>Tyr127</scene> also increases the thermostability,<scene name='10/1075247/Original_15_mutation_structure/6'>Reference | The mutation of Tyr to Gly at <scene name='10/1075247/Y127/4'>Tyr127</scene> also increases the thermostability,<scene name='10/1075247/Original_15_mutation_structure/6'>Reference Tyr127</scene>. The melting point of Y127G is increased to 87.0°C from the WT melting point of 84.7°C. Tyr has a bulky, rigid aromatic side chain that can cause structural strain, shown in <scene name='10/1075247/Y127_spacefill/1'>Y127 representation</scene>. Gly is the smallest amino acid and lacks a side chain, providing greater flexibility. The mutation <scene name='10/1075247/Y127g/2'>Y127G</scene> melting point is increased to 87.0°C. The mutation reduces [https://en.wikipedia.org/wiki/Steric_effects#:~:text=Steric%20hindrance%20is%20the%20slowing,as%20slowing%20unwanted%20side%2Dreactions. steric hindrance] and relieves strain in the protein structure, demonstrated in <scene name='10/1075247/Y127g_space_fill/1'>Y127G representation</scene>. By increasing flexibility, the Y127G mutation helps the protein maintain its folded structure under heat stress.<ref name="Tournier"/> | ||
=== Ser 283 & Asp 238 === | === Ser 283 & Asp 238 === | ||
