1k48
From Proteopedia
(New page: 200px<br /><applet load="1k48" size="450" color="white" frame="true" align="right" spinBox="true" caption="1k48" /> '''REFINED STRUCTURE AND DISULFIDE PAIRING OF T...) |
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| - | [[Image:1k48.gif|left|200px]]<br /><applet load="1k48" size=" | + | [[Image:1k48.gif|left|200px]]<br /><applet load="1k48" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1k48" /> | caption="1k48" /> | ||
'''REFINED STRUCTURE AND DISULFIDE PAIRING OF THE KALATA B1 PEPTIDE'''<br /> | '''REFINED STRUCTURE AND DISULFIDE PAIRING OF THE KALATA B1 PEPTIDE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The cyclic polypeptide kalata B1 from the African plant Oldenlandia | + | The cyclic polypeptide kalata B1 from the African plant Oldenlandia affinis DC consists of 29 amino acid residues with three disulfide linkages. In this study we used two-dimensional NMR spectroscopy to investigate the three-dimensional structure of the peptide and to determine the disulfide connectivities. Nuclear Overhauser effects (NOEs) between neighboring beta-protons of the cysteines detected at 750 MHz provided evidence for the disulfide connectivity pattern 5-13, 17-29, and 22-27. These disulfide linkages were confirmed by three-dimensional structures calculated from input constraints derived solely from NOEs without explicit disulfide connectivities. Kalata B1 is insoluble in aqueous solution above pH 3.5, but in a 50-50 water-methanol mixture, it was possible to use natural abundance two-dimensional (15)N-(1)H heteronuclear single quantum coherence spectroscopy to study the hydrophobic peptide from pH 2 to 10. The addition of methanol resulted in no significant structural changes. Although the peptide contains three prolyl residues, no evidence of multiple conformers was detected at any pH. The addition of Mn(2+) to kalata B1 resulted in selective broadening of resonances from Asn 23, Thr 24, and Glu 15; these results suggest that these three residues are involved in a specific metal binding site. |
==About this Structure== | ==About this Structure== | ||
| - | 1K48 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Oldenlandia_affinis Oldenlandia affinis]. Full crystallographic information is available from [http:// | + | 1K48 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Oldenlandia_affinis Oldenlandia affinis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1K48 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Skjeldal, L.]] | [[Category: Skjeldal, L.]] | ||
[[Category: Sletten, K.]] | [[Category: Sletten, K.]] | ||
| - | [[Category: Volkman, B | + | [[Category: Volkman, B F.]] |
[[Category: cyclic peptide]] | [[Category: cyclic peptide]] | ||
[[Category: cyclotide]] | [[Category: cyclotide]] | ||
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[[Category: uterotonic]] | [[Category: uterotonic]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:29:56 2008'' |
Revision as of 11:29, 21 February 2008
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REFINED STRUCTURE AND DISULFIDE PAIRING OF THE KALATA B1 PEPTIDE
Overview
The cyclic polypeptide kalata B1 from the African plant Oldenlandia affinis DC consists of 29 amino acid residues with three disulfide linkages. In this study we used two-dimensional NMR spectroscopy to investigate the three-dimensional structure of the peptide and to determine the disulfide connectivities. Nuclear Overhauser effects (NOEs) between neighboring beta-protons of the cysteines detected at 750 MHz provided evidence for the disulfide connectivity pattern 5-13, 17-29, and 22-27. These disulfide linkages were confirmed by three-dimensional structures calculated from input constraints derived solely from NOEs without explicit disulfide connectivities. Kalata B1 is insoluble in aqueous solution above pH 3.5, but in a 50-50 water-methanol mixture, it was possible to use natural abundance two-dimensional (15)N-(1)H heteronuclear single quantum coherence spectroscopy to study the hydrophobic peptide from pH 2 to 10. The addition of methanol resulted in no significant structural changes. Although the peptide contains three prolyl residues, no evidence of multiple conformers was detected at any pH. The addition of Mn(2+) to kalata B1 resulted in selective broadening of resonances from Asn 23, Thr 24, and Glu 15; these results suggest that these three residues are involved in a specific metal binding site.
About this Structure
1K48 is a Single protein structure of sequence from Oldenlandia affinis. Full crystallographic information is available from OCA.
Reference
Refined structure and metal binding site of the kalata B1 peptide., Skjeldal L, Gran L, Sletten K, Volkman BF, Arch Biochem Biophys. 2002 Mar 15;399(2):142-8. PMID:11888199
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