View source for 5gch


==CHEMISTRY OF CAGED ENZYMES /II$. PHOTOACTIVATION OF INHIBITED CHYMOTRYPSIN==
<StructureSection load='5gch' size='340' side='right'caption='[[5gch]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5gch]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5GCH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5GCH 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]] 2.7&#8491;</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=5gch FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5gch OCA], [https://pdbe.org/5gch PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5gch RCSB], [https://www.ebi.ac.uk/pdbsum/5gch PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5gch ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/CTRA_BOVIN CTRA_BOVIN] 
== 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/gc/5gch_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=5gch ConSurf].
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== Publication Abstract from PubMed ==
Inhibited chymotrypsin was reactivated through the photolysis of the covalently bound light-reversible cinnamates described in our previous paper [Stoddard, B.L., Bruhnke, J., Porter, N.A., Ringe, D., &amp; Petsko, G. (1990) Biochemistry 29, 4871-4879]. The light-induced deacylation was accomplished both in solution and in protein crystals, with the release of inhibitor from the crystal monitored and confirmed by X-ray diffraction. The product of photolysis has been characterized as a 3-methylcoumarin, leading to a mechanism for light-driven deacylation of an internal lactonization that is dependent on the presence of an internal hydroxyl nucleophile. The acyl enzyme formed from cinnamate A is not suitable for photochemical studies, as the complex has a short half-life in solution and does not have a chromophore that is well separated from protein absorbance. Cinnamate B, with a p-diethylamino substituent, shows an enzyme deacylation rate enhancement of 10(9) for the cis photoisomer relative to the trans starting material. The half-life and deacylation rate of this compound in the E-I complex after photon absorption have been directly measured by subsecond UV absorption studies. X-ray diffraction studies of photoactivation using a flow cell show that the cinnamate B acyl enzyme complex is fully capable of light-induced isomerization and regeneration of native enzyme in the crystalline state. The E-I complex formed upon binding of cinnamate A, however, shows little if any effect from irradiation due to competitive absorbance by the highly concentrated protein at the shorter UV wavelengths. Photolysis of cinnamate B appears to occur on a time scale fast enough for applications in crystallographic studies of enzymatic intermediate-state structures.

Photolysis and deacylation of inhibited chymotrypsin.,Stoddard BL, Bruhnke J, Koenigs P, Porter N, Ringe D, Petsko GA Biochemistry. 1990 Sep 4;29(35):8042-51. PMID:2261462<ref>PMID:2261462</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 5gch" style="background-color:#fffaf0;"></div>

==See Also==
*[[Chymotrypsin 3D structures|Chymotrypsin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bos taurus]]
[[Category: Large Structures]]
[[Category: Petsko GA]]
[[Category: Ringe D]]
[[Category: Stoddard BL]]