1epo

<table><tr><td colspan='2'>[[1epo]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Crypa Crypa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EPO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EPO FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=2Z3:N-(MORPHOLIN-4-YLCARBONYL)-L-PHENYLALANYL-N-[(1R)-1-(CYCLOHEXYLMETHYL)-3,3-DIFLUORO-2,2-DIHYDROXY-4-(METHYLAMINO)-4-OXOBUTYL]-L-NORLEUCINAMIDE'>2Z3</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Endothiapepsin Endothiapepsin], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.22 3.4.23.22] </span></td></tr>

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== Publication Abstract from PubMed ==

We report the X-ray analysis at 2.0 A resolution for crystals of the aspartic proteinase endothiapepsin (EC 3.4.23.6) complexed with a potent difluorostatone-containing tripeptide renin inhibitor (CP-81,282). The scissile bond surrogate, an electrophilic ketone, is hydrated in the complex. The pro-(R) (statine-like) hydroxyl of the tetrahedral carbonyl hydrate is hydrogen-bonded to both active-site aspartates 32 and 215 in the position occupied by a water in the native enzyme. The second hydroxyl oxygen of the hydrate is hydrogen-bonded only to the outer oxygen of Asp 32. These experimental data provide a basis for a model of the tetrahedral intermediate in aspartic proteinase-mediated cleavage of the amide bond. This indicates a mechanism in which Asp 32 is the proton donor and Asp 215 carboxylate polarizes a bound water for nucleophilic attack. The mechanism involves a carboxylate (Asp 32) that is stabilized by extensive hydrogen bonding, rather than an oxyanion derivative of the peptide as in serine proteinase catalysis.

Direct observation by X-ray analysis of the tetrahedral "intermediate" of aspartic proteinases.,Veerapandian B, Cooper JB, Sali A, Blundell TL, Rosati RL, Dominy BW, Damon DB, Hoover DJ Protein Sci. 1992 Mar;1(3):322-8. PMID:1304340<ref>PMID:1304340</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 1epo" style="background-color:#fffaf0;"></div>

*[[Proteinase|Proteinase]]

[[Category: Crypa]]

[[Category: Endothiapepsin]]

[[Category: Blundell, T L]]

[[Category: Cooper, J B]]

[[Category: Veerapandian, B]]

[[Category: Hydrolase-hydrolase inhibitor complex]]