2g8e: Difference between revisions
New page: left|200px<br /><applet load="2g8e" size="450" color="white" frame="true" align="right" spinBox="true" caption="2g8e, resolution 2.25Å" /> '''Calpain 1 proteolyti... |
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[[Image:2g8e.gif|left|200px]]<br /><applet load="2g8e" size=" | [[Image:2g8e.gif|left|200px]]<br /><applet load="2g8e" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2g8e, resolution 2.25Å" /> | caption="2g8e, resolution 2.25Å" /> | ||
'''Calpain 1 proteolytic core in complex with SNJ-1715, a cyclic hemiacetal-type inhibitor'''<br /> | '''Calpain 1 proteolytic core in complex with SNJ-1715, a cyclic hemiacetal-type inhibitor'''<br /> | ||
==Overview== | ==Overview== | ||
Calpains are intracellular calcium-activated cysteine proteases whose | Calpains are intracellular calcium-activated cysteine proteases whose unregulated proteolysis following the loss of calcium homeostasis can lead to acute degeneration during ischemic episodes and trauma, as well as Alzheimer's disease and cataract formation. The determination of the crystal structure of the proteolytic core of mu-calpain (muI-II) in a calcium-bound active conformation has made structure-guided design of active site inhibitors feasible. We present here high-resolution crystal structures of rat muI-II complexed with two reversible calpain-specific inhibitors employing cyclic hemiacetal (SNJ-1715) and alpha-ketoamide (SNJ-1945) chemistries that reveal new details about the interactions of inhibitors with this enzyme. The SNJ-1715 complex confirms that the free aldehyde is the reactive species of the cornea-permeable cyclic hemiacetal. The alpha-ketoamide warhead of SNJ-1945 binds with the hydroxyl group of the tetrahedral adduct pointing toward the catalytic histidine rather than the oxyanion hole. The muI-II-SNJ-1945 complex shows residue Glu261 displaced from the S1' site by the inhibitor, resulting in an extended "open" conformation of the domain II gating loop and an unobstructed S1' site. This conformation offers an additional template for structure-based drug design extending to the primed subsites. An important role for the highly conserved Glu261 is proposed. | ||
==About this Structure== | ==About this Structure== | ||
2G8E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus] with CA, D5G and MES as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Calpain-1 Calpain-1], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.22.52 3.4.22.52] Full crystallographic information is available from [http:// | 2G8E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=D5G:'>D5G</scene> and <scene name='pdbligand=MES:'>MES</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Calpain-1 Calpain-1], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.22.52 3.4.22.52] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2G8E OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Rattus norvegicus]] | [[Category: Rattus norvegicus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Campbell, R | [[Category: Campbell, R L.]] | ||
[[Category: Cuerrier, D.]] | [[Category: Cuerrier, D.]] | ||
[[Category: Davies, P | [[Category: Davies, P L.]] | ||
[[Category: Moldoveanu, T.]] | [[Category: Moldoveanu, T.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
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[[Category: protease]] | [[Category: protease]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:29:12 2008'' | ||
Revision as of 18:29, 21 February 2008
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Calpain 1 proteolytic core in complex with SNJ-1715, a cyclic hemiacetal-type inhibitor
OverviewOverview
Calpains are intracellular calcium-activated cysteine proteases whose unregulated proteolysis following the loss of calcium homeostasis can lead to acute degeneration during ischemic episodes and trauma, as well as Alzheimer's disease and cataract formation. The determination of the crystal structure of the proteolytic core of mu-calpain (muI-II) in a calcium-bound active conformation has made structure-guided design of active site inhibitors feasible. We present here high-resolution crystal structures of rat muI-II complexed with two reversible calpain-specific inhibitors employing cyclic hemiacetal (SNJ-1715) and alpha-ketoamide (SNJ-1945) chemistries that reveal new details about the interactions of inhibitors with this enzyme. The SNJ-1715 complex confirms that the free aldehyde is the reactive species of the cornea-permeable cyclic hemiacetal. The alpha-ketoamide warhead of SNJ-1945 binds with the hydroxyl group of the tetrahedral adduct pointing toward the catalytic histidine rather than the oxyanion hole. The muI-II-SNJ-1945 complex shows residue Glu261 displaced from the S1' site by the inhibitor, resulting in an extended "open" conformation of the domain II gating loop and an unobstructed S1' site. This conformation offers an additional template for structure-based drug design extending to the primed subsites. An important role for the highly conserved Glu261 is proposed.
About this StructureAbout this Structure
2G8E is a Single protein structure of sequence from Rattus norvegicus with , and as ligands. Active as Calpain-1, with EC number 3.4.22.52 Full crystallographic information is available from OCA.
ReferenceReference
Calpain inhibition by alpha-ketoamide and cyclic hemiacetal inhibitors revealed by X-ray crystallography., Cuerrier D, Moldoveanu T, Inoue J, Davies PL, Campbell RL, Biochemistry. 2006 Jun 20;45(24):7446-52. PMID:16768440
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