View source for 6t26


==X-ray crystal structure of Vibrio alkaline phosphatase with the non-competitive inhibitor cyclohexylamine==
<StructureSection load='6t26' size='340' side='right'caption='[[6t26]], [[Resolution|resolution]] 2.27&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6t26]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Vibrio_sp._G15-21 Vibrio sp. G15-21]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6T26 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6T26 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]] 2.265&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=HAI:CYCLOHEXYLAMMONIUM+ION'>HAI</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=6t26 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6t26 OCA], [https://pdbe.org/6t26 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6t26 RCSB], [https://www.ebi.ac.uk/pdbsum/6t26 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6t26 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q93P54_9VIBR Q93P54_9VIBR] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Background: Para-nitrophenyl phosphate, the common substrate for alkaline phosphatase (AP), is available as a cyclohexylamine salt. Here, we report that cyclohexylamine is a non-competitive inhibitor of APs. Methods: Cyclohexylamine inhibited four different APs. Co-crystallization with the cold-active Vibrio AP (VAP) was performed and the structure solved. Results: Inhibition of VAP fitted a non-competitive kinetic model (Km unchanged, Vmax reduced) with IC50 45.3 mM at the pH optimum 9.8, not sensitive to 0.5 M NaCl, and IC50 27.9 mM at pH 8.0, where the addition of 0.5 M NaCl altered the inhibition to the level observed at pH 9.8. APs from E. coli and calf intestines were less sensitive to cyclohexylamine, whereas an Antarctic bacterial AP was similar to VAP in this respect. X-ray crystallography at 2.3 A showed two binding sites, one in the active site channel and another at the surface close to dimer interface. Antarctic bacterial AP and VAP have Trp274 in common in their active-sites, that takes part in binding cyclohexylamine. VAP variants W274A, W274K, and W274H gave IC50 values of 179 mM, 188 mM and 187 mM, respectively, at pH 9.8. Conclusions: The binding of cyclohexylamine in locations at the dimeric interface and/or in the active site of APs may delay product release or reduce the rate of catalytic step(s) involving conformational changes and intersubunit communications. General significance: Cyclohexylamine is a common chemical in industries and used as a counterion in substrates for alkaline phosphatase, a clinically important and common enzyme in the biosphere.

X-ray crystal structure of Vibrio alkaline phosphatase with the non-competitive inhibitor cyclohexylamine.,Asgeirsson B, Markusson S, Hlynsdottir SS, Helland R, Hjorleifsson JG Biochem Biophys Rep. 2020 Oct 15;24:100830. doi: 10.1016/j.bbrep.2020.100830., eCollection 2020 Dec. PMID:33102813<ref>PMID:33102813</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6t26" style="background-color:#fffaf0;"></div>

==See Also==
*[[Alkaline phosphatase 3D structures|Alkaline phosphatase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Vibrio sp. G15-21]]
[[Category: Asgeirsson B]]
[[Category: Helland R]]
[[Category: Hjorleifsson JG]]
[[Category: Markusson S]]