1dhk

<StructureSection load='1dhk' size='340' side='right' caption='[[1dhk]], [[Resolution|resolution]] 1.85&Aring;' scene=''>

<table><tr><td colspan='2'>[[1dhk]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Phaseolus_vulgaris Phaseolus vulgaris] and [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DHK OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1DHK FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>

<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Alpha-amylase Alpha-amylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.1 3.2.1.1] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1dhk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1dhk OCA], [http://pdbe.org/1dhk PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1dhk RCSB], [http://www.ebi.ac.uk/pdbsum/1dhk PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1dhk ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/LEA1_PHAVU LEA1_PHAVU]] Lectin and alpha-amylase inhibitor. Acts as a defensive protein against insects.[:]

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== Publication Abstract from PubMed ==

BACKGROUND: alpha-Amylases catalyze the hydrolysis of glycosidic linkages in starch and other related polysaccharides. The alpha-amylase inhibitor (alpha-Al) from the bean Phaseolus vulgaris belongs to a family of plant defence proteins and is a potent inhibitor of mammalian alpha-amylases. The structure of pig pancreatic alpha-amylase (PPA) in complex with both a carbohydrate inhibitor (acarbose) and a proteinaceous inhibitor (Tendamistat) is known, but the catalytic mechanism is poorly understood. RESULTS: The crystal structure of pig pancreatic alpha-amylase complexed with alpha-Al was refined to 1.85 A resolution. It reveals that in complex with PPA, the inhibitor has the typical dimer structure common to legume lectins. Two hairpin loops extending out from the jellyroll fold of a monomer interact directly with the active site region of the enzyme molecule, with the inhibitor molecule filling the whole substrate-docking region of the PPA. The inhibitor makes substrate-mimetic interactions with binding subsites of the enzyme and targets catalytic residues in the active site. Binding of inhibitor induces structural changes at the active site of the enzyme. CONCLUSIONS: The present analysis reveals that there are extensive interactions between the inhibitor and residues that are highly conserved in the active site of alpha-amylases; alpha-Al1 inactivates PPA through elaborate blockage of substrate-binding sites. It provides a basis to design peptide analogue inhibitors. alpha-Amylase inhibition is of interest from several points of view, for example the treatment of diabetes and for crop protection.

 

== References ==

[[Category: Alpha-amylase]]

[[Category: Bompard-Gilles, C]]

[[Category: Payan, F]]

[[Category: Porcine]]