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==Substrate protein interactions in the limbus region of the catalytic site of Candida antarctica Lipase B==
<StructureSection load='6tp8' size='340' side='right'caption='[[6tp8]], [[Resolution|resolution]] 1.55&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6TP8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6TP8 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]] 1.55&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=DEP:DIETHYL+PHOSPHONATE'>DEP</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NTK:2,3-di(butanoyloxy)propyl+butanoate'>NTK</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=6tp8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6tp8 OCA], [https://pdbe.org/6tp8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6tp8 RCSB], [https://www.ebi.ac.uk/pdbsum/6tp8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6tp8 ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Lipases (E.C. 3.1.1.3) are ubiquitous hydrolases for the carboxyl ester bond of water-insoluble substrates such as triacylglycerols and phospholipids. Candida antarctica Lipase B (CALB) acts in aqueous as well as in low-water media, thus being of considerable biochemical significance with high interest also for its industrial applications. The hydrolysis reaction follows a two-step mechanism, or 'interfacial activation', with adsorption of the enzyme to a heterogeneous interface and subsequent enhancement of the lipolytic activity. Once positioned within the catalytic triad, substrates are then hydrolysed, and products released. However, the intermediate steps of substrate transfer from the lipidic-aqueous phase to the enzyme surface and then down to the catalytic site are still unclear. By inhibiting CALB with ethyl phosphonate and incubating with glyceryl tributyrate (2,3-di(butanoyloxy)propyl butanoate), the crystal structure of the lipid-enzyme complex, at 1.55 A resolution, shows the tributyrin in the limbus region of active site. The substrate is found 10 A above the catalytic Ser, with the glycerol backbone pre-aligned for further processing by key interactions via an extended water network with alpha-helix10 and alpha-helix5. The findings offer new elements to elucidate the mechanism of substrate recognition, transfer and catalysis of Candida antarctica Lipase B (CALB) and lipases in general.

Principles of lipid-enzyme interactions in the limbus region of the catalytic site of Candida antarctica Lipase B.,Silvestrini L, Cianci M Int J Biol Macromol. 2020 May 4;158:358-363. doi: 10.1016/j.ijbiomac.2020.04.061. PMID:32380114<ref>PMID:32380114</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 6tp8" style="background-color:#fffaf0;"></div>

==See Also==
*[[Lipase 3D Structures|Lipase 3D Structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Cianci M]]
[[Category: Silvestrini L]]