1cnn
From Proteopedia
(New page: 200px<br /><applet load="1cnn" size="450" color="white" frame="true" align="right" spinBox="true" caption="1cnn" /> '''OMEGA-CONOTOXIN MVIIC FROM CONUS MAGUS'''<br...) |
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| - | [[Image:1cnn.gif|left|200px]]<br /><applet load="1cnn" size=" | + | [[Image:1cnn.gif|left|200px]]<br /><applet load="1cnn" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1cnn" /> | caption="1cnn" /> | ||
'''OMEGA-CONOTOXIN MVIIC FROM CONUS MAGUS'''<br /> | '''OMEGA-CONOTOXIN MVIIC FROM CONUS MAGUS'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The omega-conotoxins are a set of structurally related, four-loop, six | + | The omega-conotoxins are a set of structurally related, four-loop, six cysteine containing peptides, that have a range of selectivities for different subtypes of the voltage-sensitive calcium channel (VSCC). To investigate the basis of the selectivity displayed by these peptides, we have studied the binding affinities of two naturally occurring omega-conotoxins, MVIIA and MVIIC and a series of 14 MVIIA/MVIIC loop hybrids using radioligand binding assays for N and P/Q-type Ca2+channels in rat brain tissue. A selectivity profile was developed from the ratio of relative potencies at N-type VSCCs (using [125I]GVIA radioligand binding assays) and P/Q-type VSCCs (using [125I]MVIIC radioligand binding assays). In these peptides, loops 2 and 4 make the greatest contribution to VSCC subtype selectivity, while the effects of loops 1 and 3 are negligible. Peptides with homogenous combinations of loop 2 and 4 display clear selectivity preferences, while those with heterogeneous combinations of loops 2 and 4 are less discriminatory. 1H NMR spectroscopy revealed that the global folds of MVIIA, MVIIC and the 14 loop hybrid peptides were similar; however, several differences in local structure were identified. Based on the binding data and the 3D structures of MVIIA, GVIA and MVIIC, we have developed a preliminary pharmacophore based on the omega-conotoxin residues most likely to interact with the N-type VSCC. |
==About this Structure== | ==About this Structure== | ||
| - | 1CNN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with NH2 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1CNN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CNN OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Adams, D.]] | [[Category: Adams, D.]] | ||
| - | [[Category: Alewood, P | + | [[Category: Alewood, P F.]] |
[[Category: Bond, T.]] | [[Category: Bond, T.]] | ||
| - | [[Category: Craik, D | + | [[Category: Craik, D J.]] |
| - | [[Category: Lewis, R | + | [[Category: Lewis, R J.]] |
| - | [[Category: Nielsen, K | + | [[Category: Nielsen, K J.]] |
[[Category: Thomas, L.]] | [[Category: Thomas, L.]] | ||
[[Category: NH2]] | [[Category: NH2]] | ||
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[[Category: voltage-sensitive calcium channel antagonist]] | [[Category: voltage-sensitive calcium channel antagonist]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:07:49 2008'' |
Revision as of 10:07, 21 February 2008
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OMEGA-CONOTOXIN MVIIC FROM CONUS MAGUS
Overview
The omega-conotoxins are a set of structurally related, four-loop, six cysteine containing peptides, that have a range of selectivities for different subtypes of the voltage-sensitive calcium channel (VSCC). To investigate the basis of the selectivity displayed by these peptides, we have studied the binding affinities of two naturally occurring omega-conotoxins, MVIIA and MVIIC and a series of 14 MVIIA/MVIIC loop hybrids using radioligand binding assays for N and P/Q-type Ca2+channels in rat brain tissue. A selectivity profile was developed from the ratio of relative potencies at N-type VSCCs (using [125I]GVIA radioligand binding assays) and P/Q-type VSCCs (using [125I]MVIIC radioligand binding assays). In these peptides, loops 2 and 4 make the greatest contribution to VSCC subtype selectivity, while the effects of loops 1 and 3 are negligible. Peptides with homogenous combinations of loop 2 and 4 display clear selectivity preferences, while those with heterogeneous combinations of loops 2 and 4 are less discriminatory. 1H NMR spectroscopy revealed that the global folds of MVIIA, MVIIC and the 14 loop hybrid peptides were similar; however, several differences in local structure were identified. Based on the binding data and the 3D structures of MVIIA, GVIA and MVIIC, we have developed a preliminary pharmacophore based on the omega-conotoxin residues most likely to interact with the N-type VSCC.
About this Structure
1CNN is a Single protein structure of sequence from [1] with as ligand. Full crystallographic information is available from OCA.
Reference
Structure-activity relationships of omega-conotoxins MVIIA, MVIIC and 14 loop splice hybrids at N and P/Q-type calcium channels., Nielsen KJ, Adams D, Thomas L, Bond T, Alewood PF, Craik DJ, Lewis RJ, J Mol Biol. 1999 Jun 25;289(5):1405-21. PMID:10373375
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