1gl1: Difference between revisions
New page: left|200px<br /><applet load="1gl1" size="450" color="white" frame="true" align="right" spinBox="true" caption="1gl1, resolution 2.10Å" /> '''STRUCTURE OF THE COM... |
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[[Image:1gl1.jpg|left|200px]]<br /><applet load="1gl1" size=" | [[Image:1gl1.jpg|left|200px]]<br /><applet load="1gl1" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1gl1, resolution 2.10Å" /> | caption="1gl1, resolution 2.10Å" /> | ||
'''STRUCTURE OF THE COMPLEX BETWEEN BOVINE ALPHA-CHYMOTRYPSIN AND PMP-C, AN INHIBITOR FROM THE INSECT LOCUSTA MIGRATORIA'''<br /> | '''STRUCTURE OF THE COMPLEX BETWEEN BOVINE ALPHA-CHYMOTRYPSIN AND PMP-C, AN INHIBITOR FROM THE INSECT LOCUSTA MIGRATORIA'''<br /> | ||
==Overview== | ==Overview== | ||
The crystal structures of two homologous inhibitors (PMP-C and PMP-D2v) | The crystal structures of two homologous inhibitors (PMP-C and PMP-D2v) from the insect Locusta migratoria have been determined in complex with bovine alpha-chymotrypsin at 2.1- and 3.0-A resolution, respectively. PMP-C is a potent bovine alpha-chymotrypsin inhibitor whereas native PMP-D2 is a weak inhibitor of bovine trypsin. One unique mutation at the P1 position converts PMP-D2 into a potent bovine alpha-chymotrypsin inhibitor. The two peptides have a similar overall conformation, which consists of a triple-stranded antiparallel beta-sheet connected by three disulfide bridges, thus defining a novel family of serine protease inhibitors. They have in common the protease interaction site, which is composed of the classical protease binding loop (position P5 to P'4, corresponding to residues 26-34) and of an internal segment (residues 15-18), held together by two disulfide bridges. Structural divergences between the two inhibitors result in an additional interaction site between PMP-D2v (position P10 to P6, residues 21-25) and the residues 172-175 of alpha-chymotrypsin. This unusual interaction may be responsible for species selectivity. A careful comparison of data on bound and free inhibitors (from this study and previous NMR studies, respectively) suggests that complexation to the protease stabilizes the flexible binding loop (from P5 to P'4). | ||
==About this Structure== | ==About this Structure== | ||
1GL1 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with CD as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Chymotrypsin Chymotrypsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.1 3.4.21.1] Full crystallographic information is available from [http:// | 1GL1 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=CD:'>CD</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Chymotrypsin Chymotrypsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.1 3.4.21.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GL1 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: serine protease inhibitor]] | [[Category: serine protease inhibitor]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:51:15 2008'' | ||
Revision as of 13:51, 21 February 2008
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STRUCTURE OF THE COMPLEX BETWEEN BOVINE ALPHA-CHYMOTRYPSIN AND PMP-C, AN INHIBITOR FROM THE INSECT LOCUSTA MIGRATORIA
OverviewOverview
The crystal structures of two homologous inhibitors (PMP-C and PMP-D2v) from the insect Locusta migratoria have been determined in complex with bovine alpha-chymotrypsin at 2.1- and 3.0-A resolution, respectively. PMP-C is a potent bovine alpha-chymotrypsin inhibitor whereas native PMP-D2 is a weak inhibitor of bovine trypsin. One unique mutation at the P1 position converts PMP-D2 into a potent bovine alpha-chymotrypsin inhibitor. The two peptides have a similar overall conformation, which consists of a triple-stranded antiparallel beta-sheet connected by three disulfide bridges, thus defining a novel family of serine protease inhibitors. They have in common the protease interaction site, which is composed of the classical protease binding loop (position P5 to P'4, corresponding to residues 26-34) and of an internal segment (residues 15-18), held together by two disulfide bridges. Structural divergences between the two inhibitors result in an additional interaction site between PMP-D2v (position P10 to P6, residues 21-25) and the residues 172-175 of alpha-chymotrypsin. This unusual interaction may be responsible for species selectivity. A careful comparison of data on bound and free inhibitors (from this study and previous NMR studies, respectively) suggests that complexation to the protease stabilizes the flexible binding loop (from P5 to P'4).
About this StructureAbout this Structure
1GL1 is a Protein complex structure of sequences from Bos taurus with as ligand. Active as Chymotrypsin, with EC number 3.4.21.1 Full crystallographic information is available from OCA.
ReferenceReference
Complexation of two proteic insect inhibitors to the active site of chymotrypsin suggests decoupled roles for binding and selectivity., Roussel A, Mathieu M, Dobbs A, Luu B, Cambillau C, Kellenberger C, J Biol Chem. 2001 Oct 19;276(42):38893-8. Epub 2001 Aug 8. PMID:11495915
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