1ho0: Difference between revisions
New page: left|200px<br /><applet load="1ho0" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ho0" /> '''NEW B-CHAIN MUTANT OF BOVINE INSULIN'''<br /... |
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[[Image:1ho0.jpg|left|200px]]<br /><applet load="1ho0" size=" | [[Image:1ho0.jpg|left|200px]]<br /><applet load="1ho0" size="350" color="white" frame="true" align="right" spinBox="true" | ||
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'''NEW B-CHAIN MUTANT OF BOVINE INSULIN'''<br /> | '''NEW B-CHAIN MUTANT OF BOVINE INSULIN'''<br /> | ||
==Overview== | ==Overview== | ||
The solution structure of a new B-chain mutant of bovine insulin, in which | The solution structure of a new B-chain mutant of bovine insulin, in which the cysteines B7 and B19 are replaced by two serines, has been determined by circular dichroism, 2D-NMR and molecular modeling. This structure is compared with that of the oxidized B-chain of bovine insulin [Hawkins et al. (1995) Int. J. Peptide Protein Res.46, 424-433]. Circular dichroism spectroscopy showed in particular that a higher percentage of helical secondary structure for the B-chain mutant is estimated in trifluoroethanol solution in comparison with the oxidized B-chain. 2D-NMR experiments confirmed, among multiple conformations, that the B-chain mutant presents defined secondary structures such as a alpha-helix between residues B9 and B19, and a beta-turn between amino acids B20 and B23 in aqueous trifluoroethanol. The 3D structures, which are consistent with NMR data and were obtained using a simulated annealing protocol, showed that the tertiary structure of the B-chain mutant is better resolved and is more in agreement with the insulin crystal structure than the oxidized B-chain structure described by Hawkins et al. An explanation could be the presence of two sulfonate groups in the oxidized insulin B-chain. Either by their charges and/or their size, such chemical groups could play a destructuring effect and thus could favor peptide flexibility and conformational averaging. Thus, this study provides new insights on the folding of isolated B-chains. | ||
==About this Structure== | ==About this Structure== | ||
1HO0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http:// | 1HO0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HO0 OCA]. | ||
==Reference== | ==Reference== | ||
A new B-chain mutant of insulin: comparison with the insulin crystal structure and role of sulfonate groups in the B-chain structure., Dupradeau FY, Richard T, Le Flem G, Oulyadi H, Prigent Y, Monti JP, J Pept Res. 2002 Jul;60(1):56-64. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12081626 12081626] | A new B-chain mutant of insulin: comparison with the insulin crystal structure and role of sulfonate groups in the B-chain structure., Dupradeau FY, Richard T, Le Flem G, Oulyadi H, Prigent Y, Monti JP, J Pept Res. 2002 Jul;60(1):56-64. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12081626 12081626] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Dupradeau, F | [[Category: Dupradeau, F Y.]] | ||
[[Category: Flem, G | [[Category: Flem, G Le.]] | ||
[[Category: Monti, J | [[Category: Monti, J P.]] | ||
[[Category: Oulyadi, H.]] | [[Category: Oulyadi, H.]] | ||
[[Category: Prigent, Y.]] | [[Category: Prigent, Y.]] | ||
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[[Category: beta_turn (20-23)]] | [[Category: beta_turn (20-23)]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:03:10 2008'' | ||
Revision as of 11:03, 21 February 2008
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NEW B-CHAIN MUTANT OF BOVINE INSULIN
Overview
The solution structure of a new B-chain mutant of bovine insulin, in which the cysteines B7 and B19 are replaced by two serines, has been determined by circular dichroism, 2D-NMR and molecular modeling. This structure is compared with that of the oxidized B-chain of bovine insulin [Hawkins et al. (1995) Int. J. Peptide Protein Res.46, 424-433]. Circular dichroism spectroscopy showed in particular that a higher percentage of helical secondary structure for the B-chain mutant is estimated in trifluoroethanol solution in comparison with the oxidized B-chain. 2D-NMR experiments confirmed, among multiple conformations, that the B-chain mutant presents defined secondary structures such as a alpha-helix between residues B9 and B19, and a beta-turn between amino acids B20 and B23 in aqueous trifluoroethanol. The 3D structures, which are consistent with NMR data and were obtained using a simulated annealing protocol, showed that the tertiary structure of the B-chain mutant is better resolved and is more in agreement with the insulin crystal structure than the oxidized B-chain structure described by Hawkins et al. An explanation could be the presence of two sulfonate groups in the oxidized insulin B-chain. Either by their charges and/or their size, such chemical groups could play a destructuring effect and thus could favor peptide flexibility and conformational averaging. Thus, this study provides new insights on the folding of isolated B-chains.
About this Structure
1HO0 is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
A new B-chain mutant of insulin: comparison with the insulin crystal structure and role of sulfonate groups in the B-chain structure., Dupradeau FY, Richard T, Le Flem G, Oulyadi H, Prigent Y, Monti JP, J Pept Res. 2002 Jul;60(1):56-64. PMID:12081626
Page seeded by OCA on Thu Feb 21 13:03:10 2008
