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| | <StructureSection load='4hpc' size='340' side='right'caption='[[4hpc]], [[Resolution|resolution]] 1.40Å' scene=''> | | <StructureSection load='4hpc' size='340' side='right'caption='[[4hpc]], [[Resolution|resolution]] 1.40Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4hpc]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Rhopr Rhopr]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HPC OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4HPC FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4hpc]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Rhodnius_prolixus Rhodnius prolixus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HPC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HPC FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CYS:CYSTEINE'>CYS</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CYS:CYSTEINE'>CYS</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4hpa|4hpa]], [[4hpb|4hpb]], [[4hpd|4hpd]]</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=4hpc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hpc OCA], [https://pdbe.org/4hpc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hpc RCSB], [https://www.ebi.ac.uk/pdbsum/4hpc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hpc 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=4hpc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hpc OCA], [http://pdbe.org/4hpc PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4hpc RCSB], [http://www.ebi.ac.uk/pdbsum/4hpc PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4hpc ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/NP4_RHOPR NP4_RHOPR]] Heme-based protein that deliver nitric oxide gas (NO) to the victim while feeding, resulting in vasodilation and inhibition of platelet aggregation. Also bind tightly to histamine, which is released by the host to induce wound healing (By similarity). | + | [https://www.uniprot.org/uniprot/NP4_RHOPR NP4_RHOPR] Heme-based protein that deliver nitric oxide gas (NO) to the victim while feeding, resulting in vasodilation and inhibition of platelet aggregation. Also bind tightly to histamine, which is released by the host to induce wound healing (By similarity). |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </StructureSection> | | </StructureSection> |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Rhopr]] | + | [[Category: Rhodnius prolixus]] |
| - | [[Category: Knipp, M]] | + | [[Category: Knipp M]] |
| - | [[Category: Nishikawa, K]] | + | [[Category: Nishikawa K]] |
| - | [[Category: Ogata, H]] | + | [[Category: Ogata H]] |
| - | [[Category: Heme]]
| + | |
| - | [[Category: Lipocalin]]
| + | |
| - | [[Category: Metal binding protein]]
| + | |
| - | [[Category: Nitrophorin]]
| + | |
| - | [[Category: Transport protein]]
| + | |
| Structural highlights
Function
NP4_RHOPR Heme-based protein that deliver nitric oxide gas (NO) to the victim while feeding, resulting in vasodilation and inhibition of platelet aggregation. Also bind tightly to histamine, which is released by the host to induce wound healing (By similarity).
Publication Abstract from PubMed
Nitrophorins are proteins occurring in the saliva of the blood-sucking insect Rhodnius prolixus to carry NO as a vasodilator and blood-coagulation inhibitor into the victim's tissue. It was suggested that the rate of NO release can be enhanced by the blood-plasma component L-cysteine [J.M.C.Ribeiro, Insect Biochem. Mol. Biol. 26 (1996) 899-905]. However, the mechanism of the reaction is not clear. In the attempt to exploit the reaction in detail, complexes of nitrophorin 4 (NP4) with the thiols 2-mercaptoethanol, L-cysteine, and L-homocysteine and with HS(-) were formed and characterized under anaerobic conditions using absorption spectroscopy, X-ray crystallography, and EPR spectroscopy. In contrast to met-myoglobin, which is reduced by L-cysteine, all four compounds form low-spin Fe(III) complexes with NP4. The weak equilibration constants (167-5200 M(-1)) neither support significant complexation nor the simple displacement of NO in vivo. Both amino acid based thiols form additional H-bonds with side chains of the heme pocket entry. Glutathione and L-methionine did not form a complex, indicating the specificity of the complexes with L-cysteine and L-homocysteine. Continuous wave EPR spectroscopy reveals the simultaneous existence of three low-spin systems in each case that are attributed to various protonation and/or conformational stages in the heme pocket. Electron nuclear double resonance (ENDOR) spectroscopy demonstrates that the thiol sulfurs are, at least in part, protonated. Overall, the results not only demonstrate the good accessibility of the NP4 heme center by biologically relevant thiols, but also represent the first structural characterization of a ferriheme protein in complex with L-cysteine L-homocysteine.
Complexes of ferriheme nitrophorin 4 with low-molecular weight thiol(ate)s occurring in blood plasma.,He C, Nishikawa K, Erdem OF, Reijerse E, Ogata H, Lubitz W, Knipp M J Inorg Biochem. 2013 May;122:38-48. doi: 10.1016/j.jinorgbio.2013.01.012. Epub, 2013 Feb 4. PMID:23474537[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ He C, Nishikawa K, Erdem OF, Reijerse E, Ogata H, Lubitz W, Knipp M. Complexes of ferriheme nitrophorin 4 with low-molecular weight thiol(ate)s occurring in blood plasma. J Inorg Biochem. 2013 May;122:38-48. doi: 10.1016/j.jinorgbio.2013.01.012. Epub, 2013 Feb 4. PMID:23474537 doi:http://dx.doi.org/10.1016/j.jinorgbio.2013.01.012
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