2cmy: Difference between revisions
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==Overview== | ==Overview== | ||
The storage tissues of many plants contain protease inhibitors | The storage tissues of many plants contain protease inhibitors that are believed to play an important role in defending the plant from invasion by pests and pathogens. These proteinaceous inhibitor molecules belong to a number of structurally distinct families. We describe here the isolation, purification, initial inhibitory properties, and three-dimensional structure of a novel trypsin inhibitor from seeds of Veronica hederifolia (VhTI). The VhTI peptide inhibits trypsin with a submicromolar apparent K(i) and is expected to be specific for trypsin-like serine proteases. VhTI differs dramatically in structure from all previously described families of trypsin inhibitors, consisting of a helix-turn-helix motif, with the two alpha helices tightly associated by two disulfide bonds. Unusually, the crystallized complex is in the form of a stabilized acyl-enzyme intermediate with the scissile bond of the VhTI inhibitor cleaved and the resulting N-terminal portion of the inhibitor remaining attached to the trypsin catalytic serine 195 by an ester bond. A synthetic, truncated version of the VhTI peptide has also been produced and co-crystallized with trypsin but, surprisingly, is seen to be uncleaved and consequently forms a noncovalent complex with trypsin. The VhTI peptide shows that effective enzyme inhibitors can be constructed from simple helical motifs and provides a new scaffold on which to base the design of novel serine protease inhibitors. | ||
==About this Structure== | ==About this Structure== | ||
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==Reference== | ==Reference== | ||
An unusual helix-turn-helix protease inhibitory motif in a novel trypsin inhibitor from seeds of | An unusual helix-turn-helix protease inhibitory motif in a novel trypsin inhibitor from seeds of Veronica (Veronica hederifolia L.)., Conners R, Konarev AV, Forsyth J, Lovegrove A, Marsh J, Joseph-Horne T, Shewry P, Brady RL, J Biol Chem. 2007 Sep 21;282(38):27760-8. Epub 2007 Jul 19. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17640870 17640870] | ||
[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Trypsin]] | [[Category: Trypsin]] | ||
[[Category: Veronica hederifolia]] | [[Category: Veronica hederifolia]] | ||
[[Category: Brady, R | [[Category: Brady, R L.]] | ||
[[Category: Conners, R.]] | [[Category: Conners, R.]] | ||
[[Category: Konarev, A.]] | [[Category: Konarev, A.]] | ||
[[Category: Shewry, P.]] | [[Category: Shewry, P.]] | ||
[[Category: Yardley, J | [[Category: Yardley, J L.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
[[Category: GOL]] | [[Category: GOL]] | ||
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[[Category: zymogen]] | [[Category: zymogen]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:50:22 2008'' | ||
Revision as of 17:50, 21 February 2008
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CRYSTAL COMPLEX BETWEEN BOVINE TRYPSIN AND VERONICA HEDERIFOLIA TRYPSIN INHIBITOR
OverviewOverview
The storage tissues of many plants contain protease inhibitors that are believed to play an important role in defending the plant from invasion by pests and pathogens. These proteinaceous inhibitor molecules belong to a number of structurally distinct families. We describe here the isolation, purification, initial inhibitory properties, and three-dimensional structure of a novel trypsin inhibitor from seeds of Veronica hederifolia (VhTI). The VhTI peptide inhibits trypsin with a submicromolar apparent K(i) and is expected to be specific for trypsin-like serine proteases. VhTI differs dramatically in structure from all previously described families of trypsin inhibitors, consisting of a helix-turn-helix motif, with the two alpha helices tightly associated by two disulfide bonds. Unusually, the crystallized complex is in the form of a stabilized acyl-enzyme intermediate with the scissile bond of the VhTI inhibitor cleaved and the resulting N-terminal portion of the inhibitor remaining attached to the trypsin catalytic serine 195 by an ester bond. A synthetic, truncated version of the VhTI peptide has also been produced and co-crystallized with trypsin but, surprisingly, is seen to be uncleaved and consequently forms a noncovalent complex with trypsin. The VhTI peptide shows that effective enzyme inhibitors can be constructed from simple helical motifs and provides a new scaffold on which to base the design of novel serine protease inhibitors.
About this StructureAbout this Structure
2CMY is a Protein complex structure of sequences from Bos taurus and Veronica hederifolia with , and as ligands. Active as Trypsin, with EC number 3.4.21.4 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
An unusual helix-turn-helix protease inhibitory motif in a novel trypsin inhibitor from seeds of Veronica (Veronica hederifolia L.)., Conners R, Konarev AV, Forsyth J, Lovegrove A, Marsh J, Joseph-Horne T, Shewry P, Brady RL, J Biol Chem. 2007 Sep 21;282(38):27760-8. Epub 2007 Jul 19. PMID:17640870
Page seeded by OCA on Thu Feb 21 16:50:22 2008