View source for 2ra3


==Human cationic trypsin complexed with bovine pancreatic trypsin inhibitor (BPTI)==
<StructureSection load='2ra3' size='340' side='right'caption='[[2ra3]], [[Resolution|resolution]] 1.46&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2ra3]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus] and [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2RA3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2RA3 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.46&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2ra3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ra3 OCA], [https://pdbe.org/2ra3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ra3 RCSB], [https://www.ebi.ac.uk/pdbsum/2ra3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ra3 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/TRY1_HUMAN TRY1_HUMAN] Defects in PRSS1 are a cause of pancreatitis (PCTT) [MIM:[https://omim.org/entry/167800 167800]. A disease characterized by the presence of calculi in pancreatic ducts. It causes severe abdominal pain attacks.<ref>PMID:10930381</ref> <ref>PMID:8841182</ref> <ref>PMID:11866271</ref> <ref>PMID:9322498</ref> <ref>PMID:9633818</ref> <ref>PMID:10381903</ref> <ref>PMID:10204851</ref> <ref>PMID:11073545</ref> <ref>PMID:11788572</ref> <ref>PMID:14695529</ref> <ref>PMID:15776435</ref> 
== Function ==
[https://www.uniprot.org/uniprot/TRY1_HUMAN TRY1_HUMAN] Has activity against the synthetic substrates Boc-Phe-Ser-Arg-Mec, Boc-Leu-Thr-Arg-Mec, Boc-Gln-Ala-Arg-Mec and Boc-Val-Pro-Arg-Mec. The single-chain form is more active than the two-chain form against all of these substrates.<ref>PMID:7945238</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ra/2ra3_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2ra3 ConSurf].
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== Publication Abstract from PubMed ==
Human mesotrypsin is an isoform of trypsin that displays unusual resistance to polypeptide trypsin inhibitors and has been observed to cleave several such inhibitors as substrates. Whereas substitution of arginine for the highly conserved glycine 193 in the trypsin active site has been implicated as a critical factor in the inhibitor resistance of mesotrypsin, how this substitution leads to accelerated inhibitor cleavage is not clear. Bovine pancreatic trypsin inhibitor (BPTI) forms an extremely stable and cleavage-resistant complex with trypsin, and thus provides a rigorous challenge of mesotrypsin catalytic activity toward polypeptide inhibitors. Here, we report kinetic constants for mesotrypsin and the highly homologous (but inhibitor sensitive) human cationic trypsin, describing inhibition by, and cleavage of BPTI, as well as crystal structures of the mesotrypsin-BPTI and human cationic trypsin-BPTI complexes. We find that mesotrypsin cleaves BPTI with a rate constant accelerated 350-fold over that of human cationic trypsin and 150,000-fold over that of bovine trypsin. From the crystal structures, we see that small conformational adjustments limited to several side chains enable mesotrypsin-BPTI complex formation, surmounting the predicted steric clash introduced by Arg-193. Our results show that the mesotrypsin-BPTI interface favors catalysis through (a) electrostatic repulsion between the closely spaced mesotrypsin Arg-193 and BPTI Arg-17, and (b) elimination of two hydrogen bonds between the enzyme and the amine leaving group portion of BPTI. Our model predicts that these deleterious interactions accelerate leaving group dissociation and deacylation.

Structural basis for accelerated cleavage of bovine pancreatic trypsin inhibitor (BPTI) by human mesotrypsin.,Salameh MA, Soares AS, Hockla A, Radisky ES J Biol Chem. 2008 Feb 15;283(7):4115-23. Epub 2007 Dec 12. PMID:18077447<ref>PMID:18077447</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[BPTI 3D structures|BPTI 3D structures]]
*[[Trypsin 3D structures|Trypsin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bos taurus]]
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Radisky ES]]
[[Category: Salameh MA]]
[[Category: Soares AS]]