5ff1: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
==Two way mode of binding of antithyroid drug methimazole to mammalian heme peroxidases: Structure of the complex of lactoperoxidase with methimazole at 1.97 Angstrom resolution== | ==Two way mode of binding of antithyroid drug methimazole to mammalian heme peroxidases: Structure of the complex of lactoperoxidase with methimazole at 1.97 Angstrom resolution== | ||
<StructureSection load='5ff1' size='340' side='right' caption='[[5ff1]], [[Resolution|resolution]] 1.97Å' scene=''> | <StructureSection load='5ff1' size='340' side='right' caption='[[5ff1]], [[Resolution|resolution]] 1.97Å' scene=''> | ||
| Line 5: | Line 6: | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MMZ:1-METHYL-1,3-DIHYDRO-2H-IMIDAZOLE-2-THIONE'>MMZ</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NO3:NITRATE+ION'>NO3</scene></td></tr> | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MMZ:1-METHYL-1,3-DIHYDRO-2H-IMIDAZOLE-2-THIONE'>MMZ</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NO3:NITRATE+ION'>NO3</scene></td></tr> | ||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4qjq|4qjq]]</td></tr> | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4qjq|4qjq]]</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=5ff1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ff1 OCA], [http://pdbe.org/5ff1 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5ff1 RCSB], [http://www.ebi.ac.uk/pdbsum/5ff1 PDBsum]</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=5ff1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ff1 OCA], [http://pdbe.org/5ff1 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5ff1 RCSB], [http://www.ebi.ac.uk/pdbsum/5ff1 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5ff1 ProSAT]</span></td></tr> | ||
</table> | </table> | ||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Lactoperoxidase (LPO, EC 1.11.1.7) is a member of the mammalian heme peroxidase family which also includes thyroid peroxidase (TPO). These two enzymes have a sequence homology of 76%. The structure of LPO is known but not that of TPO. In order to determine the mode of binding of antithyroid drugs to thyroid peroxidase, we have determined the crystal structure of LPO complexed with an antithyroid drug, methimazole (MMZ) at 1.97 A resolution. LPO was isolated from caprine colostrum, purified to homogeneity and crystallized with 20% poly(ethylene glycol)-3350. Crystals of LPO were soaked in a reservoir solution containing MMZ. The structure determination showed the presence of two crystallographically independent molecules in the asymmetric unit. Both molecules contained one molecule of MMZ, but with different orientations. MMZ was held tightly between the heme moiety on one side and the hydrophobic parts of the side chains of Arg255, Glu258, and Leu262 on the opposite side. The back of the cleft contained the side chains of Gln105 and His109 which also interacted with MMZ. In both orientations, MMZ had identical buried areas and formed a similar number of interactions. It appears that the molecules of MMZ can enter the substrate-binding channel of LPO in two opposite orientations. But once they reach the distal heme pocket, their orientations are frozen due to equally tight packing of MMZ in both orientations. This is a novel example of an inhibitor binding to an enzyme with two orientations at the same site with nearly equal occupancies. | |||
Dual binding mode of antithyroid drug methimazole to mammalian heme peroxidases - structural determination of the lactoperoxidase-methimazole complex at 1.97 A resolution.,Singh RP, Singh A, Sirohi HV, Singh AK, Kaur P, Sharma S, Singh TP FEBS Open Bio. 2016 Jun 14;6(7):640-50. doi: 10.1002/2211-5463.12051. eCollection, 2016 Jul. PMID:27398304<ref>PMID:27398304</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 5ff1" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Revision as of 10:58, 27 July 2016
Two way mode of binding of antithyroid drug methimazole to mammalian heme peroxidases: Structure of the complex of lactoperoxidase with methimazole at 1.97 Angstrom resolutionTwo way mode of binding of antithyroid drug methimazole to mammalian heme peroxidases: Structure of the complex of lactoperoxidase with methimazole at 1.97 Angstrom resolution
Structural highlights
Publication Abstract from PubMedLactoperoxidase (LPO, EC 1.11.1.7) is a member of the mammalian heme peroxidase family which also includes thyroid peroxidase (TPO). These two enzymes have a sequence homology of 76%. The structure of LPO is known but not that of TPO. In order to determine the mode of binding of antithyroid drugs to thyroid peroxidase, we have determined the crystal structure of LPO complexed with an antithyroid drug, methimazole (MMZ) at 1.97 A resolution. LPO was isolated from caprine colostrum, purified to homogeneity and crystallized with 20% poly(ethylene glycol)-3350. Crystals of LPO were soaked in a reservoir solution containing MMZ. The structure determination showed the presence of two crystallographically independent molecules in the asymmetric unit. Both molecules contained one molecule of MMZ, but with different orientations. MMZ was held tightly between the heme moiety on one side and the hydrophobic parts of the side chains of Arg255, Glu258, and Leu262 on the opposite side. The back of the cleft contained the side chains of Gln105 and His109 which also interacted with MMZ. In both orientations, MMZ had identical buried areas and formed a similar number of interactions. It appears that the molecules of MMZ can enter the substrate-binding channel of LPO in two opposite orientations. But once they reach the distal heme pocket, their orientations are frozen due to equally tight packing of MMZ in both orientations. This is a novel example of an inhibitor binding to an enzyme with two orientations at the same site with nearly equal occupancies. Dual binding mode of antithyroid drug methimazole to mammalian heme peroxidases - structural determination of the lactoperoxidase-methimazole complex at 1.97 A resolution.,Singh RP, Singh A, Sirohi HV, Singh AK, Kaur P, Sharma S, Singh TP FEBS Open Bio. 2016 Jun 14;6(7):640-50. doi: 10.1002/2211-5463.12051. eCollection, 2016 Jul. PMID:27398304[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
|
| ||||||||||||||||||