1t9e
From Proteopedia
(New page: 200px<br /><applet load="1t9e" size="450" color="white" frame="true" align="right" spinBox="true" caption="1t9e" /> '''NMR solution structure of a disulfide analog...) |
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| - | [[Image:1t9e.gif|left|200px]]<br /><applet load="1t9e" size=" | + | [[Image:1t9e.gif|left|200px]]<br /><applet load="1t9e" size="350" color="white" frame="true" align="right" spinBox="true" |
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'''NMR solution structure of a disulfide analogue of the cyclic sunflower trypsin inhibitor SFTI-1'''<br /> | '''NMR solution structure of a disulfide analogue of the cyclic sunflower trypsin inhibitor SFTI-1'''<br /> | ||
==Overview== | ==Overview== | ||
| - | SFTI-1 is a novel 14 amino acid peptide comprised of a circular backbone | + | SFTI-1 is a novel 14 amino acid peptide comprised of a circular backbone constrained by three proline residues, a hydrogen-bond network, and a single disulfide bond. It is the smallest and most potent known Bowman-Birk trypsin inhibitor and the only one with a cyclic peptidic backbone. The solution structure of [ABA(3,11)]SFTI-1, a disulfide-deficient analogue of SFTI-1, has been determined by (1)H NMR spectroscopy. The lowest energy structures of native SFTI-1 and [ABA(3,11)]SFTI-1 are similar and superimpose with a root-mean-square deviation over the backbone and heavy atoms of 0.26 +/- 0.09 and 1.10 +/- 0.22 A, respectively. The disulfide bridge in SFTI-1 was found to be a minor determinant for the overall structure, but its removal resulted in a slightly weakened hydrogen-bonding network. To further investigate the role of the disulfide bridge, NMR chemical shifts for the backbone H(alpha) protons of two disulfide-deficient linear analogues of SFTI-1, [ABA(3,11)]SFTI-1[6,5] and [ABA(3,11)]SFTI-1[1,14] were measured. These correspond to analogues of the cleavage product of SFTI-1 and a putative biosynthetic precursor, respectively. In contrast with the cyclic peptide, it was found that the disulfide bridge is essential for maintaining the structure of these open-chain analogues. Overall, the hydrogen-bond network appears to be a crucial determinant of the structure of SFTI-1 analogues. |
==About this Structure== | ==About this Structure== | ||
| - | 1T9E 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:// | + | 1T9E 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=1T9E OCA]. |
==Reference== | ==Reference== | ||
Disulfide bond mutagenesis and the structure and function of the head-to-tail macrocyclic trypsin inhibitor SFTI-1., Korsinczky ML, Clark RJ, Craik DJ, Biochemistry. 2005 Feb 1;44(4):1145-53. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=15667208 15667208] | Disulfide bond mutagenesis and the structure and function of the head-to-tail macrocyclic trypsin inhibitor SFTI-1., Korsinczky ML, Clark RJ, Craik DJ, Biochemistry. 2005 Feb 1;44(4):1145-53. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=15667208 15667208] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Clark, R | + | [[Category: Clark, R J.]] |
| - | [[Category: Craik, D | + | [[Category: Craik, D J.]] |
| - | [[Category: Korsinczky, M | + | [[Category: Korsinczky, M L.J.]] |
[[Category: disulfide mutant]] | [[Category: disulfide mutant]] | ||
[[Category: nmr]] | [[Category: nmr]] | ||
[[Category: sunflower trypsin inhibitor]] | [[Category: sunflower trypsin inhibitor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:11:18 2008'' |
Revision as of 13:11, 21 February 2008
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NMR solution structure of a disulfide analogue of the cyclic sunflower trypsin inhibitor SFTI-1
Overview
SFTI-1 is a novel 14 amino acid peptide comprised of a circular backbone constrained by three proline residues, a hydrogen-bond network, and a single disulfide bond. It is the smallest and most potent known Bowman-Birk trypsin inhibitor and the only one with a cyclic peptidic backbone. The solution structure of [ABA(3,11)]SFTI-1, a disulfide-deficient analogue of SFTI-1, has been determined by (1)H NMR spectroscopy. The lowest energy structures of native SFTI-1 and [ABA(3,11)]SFTI-1 are similar and superimpose with a root-mean-square deviation over the backbone and heavy atoms of 0.26 +/- 0.09 and 1.10 +/- 0.22 A, respectively. The disulfide bridge in SFTI-1 was found to be a minor determinant for the overall structure, but its removal resulted in a slightly weakened hydrogen-bonding network. To further investigate the role of the disulfide bridge, NMR chemical shifts for the backbone H(alpha) protons of two disulfide-deficient linear analogues of SFTI-1, [ABA(3,11)]SFTI-1[6,5] and [ABA(3,11)]SFTI-1[1,14] were measured. These correspond to analogues of the cleavage product of SFTI-1 and a putative biosynthetic precursor, respectively. In contrast with the cyclic peptide, it was found that the disulfide bridge is essential for maintaining the structure of these open-chain analogues. Overall, the hydrogen-bond network appears to be a crucial determinant of the structure of SFTI-1 analogues.
About this Structure
1T9E is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Disulfide bond mutagenesis and the structure and function of the head-to-tail macrocyclic trypsin inhibitor SFTI-1., Korsinczky ML, Clark RJ, Craik DJ, Biochemistry. 2005 Feb 1;44(4):1145-53. PMID:15667208
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