2a2r
From Proteopedia
(New page: 200px<br /> <applet load="2a2r" size="450" color="white" frame="true" align="right" spinBox="true" caption="2a2r, resolution 1.4Å" /> '''Crystal Structure of...) |
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| - | [[Image:2a2r.gif|left|200px]]<br /> | + | [[Image:2a2r.gif|left|200px]]<br /><applet load="2a2r" size="350" color="white" frame="true" align="right" spinBox="true" |
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caption="2a2r, resolution 1.4Å" /> | caption="2a2r, resolution 1.4Å" /> | ||
'''Crystal Structure of Glutathione Transferase Pi in complex with S-nitrosoglutathione'''<br /> | '''Crystal Structure of Glutathione Transferase Pi in complex with S-nitrosoglutathione'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The nitric oxide molecule (NO) is involved in many important physiological | + | The nitric oxide molecule (NO) is involved in many important physiological processes and seems to be stabilized by reduced thiol species, such as S-nitrosoglutathione (GSNO). GSNO binds strongly to glutathione transferases, a major superfamily of detoxifying enzymes. We have determined the crystal structure of GSNO bound to dimeric human glutathione transferase P1-1 (hGSTP1-1) at 1.4 A resolution. The GSNO ligand binds in the active site with the nitrosyl moiety involved in multiple interactions with the protein. Isothermal titration calorimetry and differential scanning calorimetry (DSC) have been used to characterize the interaction of GSNO with the enzyme. The binding of GSNO to wild-type hGSTP1-1 induces a negative cooperativity with a kinetic process concomitant to the binding process occurring at more physiological temperatures. GSNO inhibits wild-type enzyme competitively at lower temperatures but covalently at higher temperatures, presumably by S-nitrosylation of a sulfhydryl group. The C47S mutation removes the covalent modification potential of the enzyme by GSNO. These results are consistent with a model in which the flexible helix alpha2 of hGST P1-1 must move sufficiently to allow chemical modification of Cys47. In contrast to wild-type enzyme, the C47S mutation induces a positive cooperativity toward GSNO binding. The DSC results show that the thermal stability of the mutant is slightly higher than wild type, consistent with helix alpha2 forming new interactions with the other subunit. All these results suggest that Cys47 plays a key role in intersubunit cooperativity and that under certain pathological conditions S-nitrosylation of Cys47 by GSNO is a likely physiological scenario. |
==About this Structure== | ==About this Structure== | ||
| - | 2A2R is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with CA, CO3, MES and GSN as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glutathione_transferase Glutathione transferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.18 2.5.1.18] Full crystallographic information is available from [http:// | + | 2A2R is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=CO3:'>CO3</scene>, <scene name='pdbligand=MES:'>MES</scene> and <scene name='pdbligand=GSN:'>GSN</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glutathione_transferase Glutathione transferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.18 2.5.1.18] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A2R OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Adams, J | + | [[Category: Adams, J J.]] |
| - | [[Category: Morton, C | + | [[Category: Morton, C J.]] |
| - | [[Category: Parker, L | + | [[Category: Parker, L J.]] |
| - | [[Category: Parker, M | + | [[Category: Parker, M W.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: CO3]] | [[Category: CO3]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:23:02 2008'' |
Revision as of 14:23, 21 February 2008
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Crystal Structure of Glutathione Transferase Pi in complex with S-nitrosoglutathione
Overview
The nitric oxide molecule (NO) is involved in many important physiological processes and seems to be stabilized by reduced thiol species, such as S-nitrosoglutathione (GSNO). GSNO binds strongly to glutathione transferases, a major superfamily of detoxifying enzymes. We have determined the crystal structure of GSNO bound to dimeric human glutathione transferase P1-1 (hGSTP1-1) at 1.4 A resolution. The GSNO ligand binds in the active site with the nitrosyl moiety involved in multiple interactions with the protein. Isothermal titration calorimetry and differential scanning calorimetry (DSC) have been used to characterize the interaction of GSNO with the enzyme. The binding of GSNO to wild-type hGSTP1-1 induces a negative cooperativity with a kinetic process concomitant to the binding process occurring at more physiological temperatures. GSNO inhibits wild-type enzyme competitively at lower temperatures but covalently at higher temperatures, presumably by S-nitrosylation of a sulfhydryl group. The C47S mutation removes the covalent modification potential of the enzyme by GSNO. These results are consistent with a model in which the flexible helix alpha2 of hGST P1-1 must move sufficiently to allow chemical modification of Cys47. In contrast to wild-type enzyme, the C47S mutation induces a positive cooperativity toward GSNO binding. The DSC results show that the thermal stability of the mutant is slightly higher than wild type, consistent with helix alpha2 forming new interactions with the other subunit. All these results suggest that Cys47 plays a key role in intersubunit cooperativity and that under certain pathological conditions S-nitrosylation of Cys47 by GSNO is a likely physiological scenario.
About this Structure
2A2R is a Single protein structure of sequence from Homo sapiens with , , and as ligands. Active as Glutathione transferase, with EC number 2.5.1.18 Full crystallographic information is available from OCA.
Reference
Calorimetric and structural studies of the nitric oxide carrier S-nitrosoglutathione bound to human glutathione transferase P1-1., Tellez-Sanz R, Cesareo E, Nuccetelli M, Aguilera AM, Baron C, Parker LJ, Adams JJ, Morton CJ, Lo Bello M, Parker MW, Garcia-Fuentes L, Protein Sci. 2006 May;15(5):1093-105. Epub 2006 Apr 5. PMID:16597834
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