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| | ==Lipoxygenase-1 (soybean) L546A/L754A mutant== | | ==Lipoxygenase-1 (soybean) L546A/L754A mutant== |
| - | <StructureSection load='4wha' size='340' side='right' caption='[[4wha]], [[Resolution|resolution]] 1.70Å' scene=''> | + | <StructureSection load='4wha' size='340' side='right'caption='[[4wha]], [[Resolution|resolution]] 1.70Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4wha]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4WHA OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4WHA FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4wha]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Glycine_max Glycine max]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4WHA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4WHA FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.7Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3pzw|3pzw]]</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Oxidoreductase Oxidoreductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.13.11.12 1.13.11.12] </span></td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4wha FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4wha OCA], [https://pdbe.org/4wha PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4wha RCSB], [https://www.ebi.ac.uk/pdbsum/4wha PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4wha ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4wha FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4wha OCA], [http://pdbe.org/4wha PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4wha RCSB], [http://www.ebi.ac.uk/pdbsum/4wha PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4wha ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/LOX1_SOYBN LOX1_SOYBN]] Plant lipoxygenase may be involved in a number of diverse aspects of plant physiology including growth and development, pest resistance, and senescence or responses to wounding. With linoleate as substrate, L-1 shows a preference for carbon 13 as the site for hydroperoxidation (in contrast to L-2 and L-3, which utilize either carbon 9 or 13). At pH above 8.5, only (9Z,11E,13S)-13-hydroperoxyoctadeca-9,11-dienoate is produced, but as the pH decreases, the proportion of (9S)-hydroperoxide increases linearly until at pH 6.0 it represents about 25 % of the products.<ref>PMID:16157595</ref> | + | [https://www.uniprot.org/uniprot/LOX1_SOYBN LOX1_SOYBN] Plant lipoxygenase may be involved in a number of diverse aspects of plant physiology including growth and development, pest resistance, and senescence or responses to wounding. With linoleate as substrate, L-1 shows a preference for carbon 13 as the site for hydroperoxidation (in contrast to L-2 and L-3, which utilize either carbon 9 or 13). At pH above 8.5, only (9Z,11E,13S)-13-hydroperoxyoctadeca-9,11-dienoate is produced, but as the pH decreases, the proportion of (9S)-hydroperoxide increases linearly until at pH 6.0 it represents about 25 % of the products.<ref>PMID:16157595</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Oxidoreductase]] | + | [[Category: Glycine max]] |
| - | [[Category: Carr, C A.M]] | + | [[Category: Large Structures]] |
| - | [[Category: Hu, S]] | + | [[Category: Carr CAM]] |
| - | [[Category: Klinman, J P]] | + | [[Category: Hu S]] |
| - | [[Category: Scouras, A D]] | + | [[Category: Klinman JP]] |
| - | [[Category: C-h activation]] | + | [[Category: Scouras AD]] |
| - | [[Category: Lipoxygenase]]
| + | |
| - | [[Category: Tunneling]]
| + | |
| Structural highlights
Function
LOX1_SOYBN Plant lipoxygenase may be involved in a number of diverse aspects of plant physiology including growth and development, pest resistance, and senescence or responses to wounding. With linoleate as substrate, L-1 shows a preference for carbon 13 as the site for hydroperoxidation (in contrast to L-2 and L-3, which utilize either carbon 9 or 13). At pH above 8.5, only (9Z,11E,13S)-13-hydroperoxyoctadeca-9,11-dienoate is produced, but as the pH decreases, the proportion of (9S)-hydroperoxide increases linearly until at pH 6.0 it represents about 25 % of the products.[1]
Publication Abstract from PubMed
The enzyme soybean lipoxygenase (SLO) has served as a prototype for hydrogen-tunneling reactions, as a result of its unusual kinetic isotope effects (KIEs) and their temperature dependencies. Using a synergy of kinetic, structural, and theoretical studies, we show how the interplay between donor-acceptor distance and active-site flexibility leads to catalytic behavior previously predicted by quantum tunneling theory. Modification of the size of two hydrophobic residues by site-specific mutagenesis in SLO reduces the reaction rate 10(4)-fold and is accompanied by an enormous and unprecedented room-temperature KIE. Fitting of the kinetic data to a non-adiabatic model implicates an expansion of the active site that cannot be compensated by donor-acceptor distance sampling. A 1.7 A resolution X-ray structure of the double mutant further indicates an unaltered backbone conformation, almost identical side-chain conformations, and a significantly enlarged active-site cavity. These findings show the compelling property of room-temperature hydrogen tunneling within a biological context and demonstrate the very high sensitivity of such tunneling to barrier width.
Extremely elevated room-temperature kinetic isotope effects quantify the critical role of barrier width in enzymatic C-H activation.,Hu S, Sharma SC, Scouras AD, Soudackov AV, Carr CA, Hammes-Schiffer S, Alber T, Klinman JP J Am Chem Soc. 2014 Jun 11;136(23):8157-60. doi: 10.1021/ja502726s. Epub 2014 Jun, 2. PMID:24884374[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Coffa G, Imber AN, Maguire BC, Laxmikanthan G, Schneider C, Gaffney BJ, Brash AR. On the relationships of substrate orientation, hydrogen abstraction, and product stereochemistry in single and double dioxygenations by soybean lipoxygenase-1 and its Ala542Gly mutant. J Biol Chem. 2005 Nov 18;280(46):38756-66. Epub 2005 Sep 12. PMID:16157595 doi:http://dx.doi.org/10.1074/jbc.M504870200
- ↑ Hu S, Sharma SC, Scouras AD, Soudackov AV, Carr CA, Hammes-Schiffer S, Alber T, Klinman JP. Extremely elevated room-temperature kinetic isotope effects quantify the critical role of barrier width in enzymatic C-H activation. J Am Chem Soc. 2014 Jun 11;136(23):8157-60. doi: 10.1021/ja502726s. Epub 2014 Jun, 2. PMID:24884374 doi:http://dx.doi.org/10.1021/ja502726s
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