1brb: Difference between revisions
New page: left|200px<br /><applet load="1brb" size="450" color="white" frame="true" align="right" spinBox="true" caption="1brb, resolution 2.1Å" /> '''CRYSTAL STRUCTURES OF... |
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[[Image:1brb.gif|left|200px]]<br /><applet load="1brb" size=" | [[Image:1brb.gif|left|200px]]<br /><applet load="1brb" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1brb, resolution 2.1Å" /> | caption="1brb, resolution 2.1Å" /> | ||
'''CRYSTAL STRUCTURES OF RAT ANIONIC TRYPSIN COMPLEXED WITH THE PROTEIN INHIBITORS APPI AND BPTI'''<br /> | '''CRYSTAL STRUCTURES OF RAT ANIONIC TRYPSIN COMPLEXED WITH THE PROTEIN INHIBITORS APPI AND BPTI'''<br /> | ||
==Overview== | ==Overview== | ||
The crystal structure of rat anionic trypsin D189G/G226D has been | The crystal structure of rat anionic trypsin D189G/G226D has been determined in complexes with each of the protein inhibitors APPI (amyloid beta-protein precursor inhibitor domain) and BPTI (bovine pancreatic trypsin inhibitor) at resolutions of 2.5 A and 2.1 A, respectively. Comparisons with the structure of the bovine trypsin-BPTI complex show that the enzyme-inhibitor interactions in rat trypsin are dominated to a much greater degree by attractive and repulsive electrostatic forces. Decreased structural complementarity in the flanking regions of the interface formed with BPTI is reflected in significantly weaker inhibition relative to bovine trypsin. The primary active site loop of BPTI adopts slightly different conformations when bound to rat and cow trypsins, reflecting a broader entrance to the binding pocket in the former. Tight complementarity of each loop conformer to the respective active sites then gives rise to significantly different overall orientations of the inhibitor when bound to the two enzymes. The crystal structures of trypsin bound to these protein inhibitors are excellent models of the Michaelis complexes, which permit visualization of substrate interactions both N and C-terminal to the cleaved bond, while maintaining identical reaction chemistry. They will be uniquely useful to the structure-function analysis of variant rat trypsin enzymes. | ||
==About this Structure== | ==About this Structure== | ||
1BRB is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Active as [http://en.wikipedia.org/wiki/Trypsin Trypsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.4 3.4.21.4] Full crystallographic information is available from [http:// | 1BRB is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Active as [http://en.wikipedia.org/wiki/Trypsin Trypsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.4 3.4.21.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BRB OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Rattus norvegicus]] | [[Category: Rattus norvegicus]] | ||
[[Category: Trypsin]] | [[Category: Trypsin]] | ||
[[Category: Fletterick, R | [[Category: Fletterick, R J.]] | ||
[[Category: Perona, J | [[Category: Perona, J J.]] | ||
[[Category: complex(proteinase/inhibitor)]] | [[Category: complex(proteinase/inhibitor)]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:58:18 2008'' | ||
Revision as of 12:58, 21 February 2008
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CRYSTAL STRUCTURES OF RAT ANIONIC TRYPSIN COMPLEXED WITH THE PROTEIN INHIBITORS APPI AND BPTI
OverviewOverview
The crystal structure of rat anionic trypsin D189G/G226D has been determined in complexes with each of the protein inhibitors APPI (amyloid beta-protein precursor inhibitor domain) and BPTI (bovine pancreatic trypsin inhibitor) at resolutions of 2.5 A and 2.1 A, respectively. Comparisons with the structure of the bovine trypsin-BPTI complex show that the enzyme-inhibitor interactions in rat trypsin are dominated to a much greater degree by attractive and repulsive electrostatic forces. Decreased structural complementarity in the flanking regions of the interface formed with BPTI is reflected in significantly weaker inhibition relative to bovine trypsin. The primary active site loop of BPTI adopts slightly different conformations when bound to rat and cow trypsins, reflecting a broader entrance to the binding pocket in the former. Tight complementarity of each loop conformer to the respective active sites then gives rise to significantly different overall orientations of the inhibitor when bound to the two enzymes. The crystal structures of trypsin bound to these protein inhibitors are excellent models of the Michaelis complexes, which permit visualization of substrate interactions both N and C-terminal to the cleaved bond, while maintaining identical reaction chemistry. They will be uniquely useful to the structure-function analysis of variant rat trypsin enzymes.
About this StructureAbout this Structure
1BRB is a Protein complex structure of sequences from Rattus norvegicus. Active as Trypsin, with EC number 3.4.21.4 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of rat anionic trypsin complexed with the protein inhibitors APPI and BPTI., Perona JJ, Tsu CA, Craik CS, Fletterick RJ, J Mol Biol. 1993 Apr 5;230(3):919-33. PMID:7683059
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