1b2y: Difference between revisions

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New page: left|200px<br /> <applet load="1b2y" size="450" color="white" frame="true" align="right" spinBox="true" caption="1b2y, resolution 3.2Å" /> '''STRUCTURE OF HUMAN P...
 
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[[Image:1b2y.gif|left|200px]]<br />
<applet load="1b2y" size="450" color="white" frame="true" align="right" spinBox="true"
caption="1b2y, resolution 3.2&Aring;" />
'''STRUCTURE OF HUMAN PANCREATIC ALPHA-AMYLASE IN COMPLEX WITH THE CARBOHYDRATE INHIBITOR ACARBOSE'''<br />


==Overview==
==STRUCTURE OF HUMAN PANCREATIC ALPHA-AMYLASE IN COMPLEX WITH THE CARBOHYDRATE INHIBITOR ACARBOSE==
An X-ray structure analysis of a crystal of pig pancreatic alpha-amylase, (EC 3.2.1.1) that was soaked with acarbose (a pseudotetrasaccharide, alpha-amylase inhibitor) showed electron density corresponding to five, fully occupied subsites in the active site. The crystal structure was, refined to an R-factor of 15.3%, with a root mean square deviation in bond, distances of 0.015 A. The model includes all 496 residues of the enzyme, one calcium ion, one chloride ion, 393 water molecules, and five bound, sugar rings. The pseudodisaccharide acarviosine that is the essential, structural unit responsible for the activity of all inhibitors of the, acarbose type was located at the catalytic center. The carboxylic oxygens, of the catalytically competent residues Glu233 and Asp300 form hydrogen, bonds with the "glycosidic" NH group of the acarviosine group. The third, residue of the catalytic triad Asp197 is located on the opposite side of, the inhibitor binding cleft with one of its carbonyl oxygens at a 3.3-A, distance from the anomeric carbon C-1 of the inhibitor center. Binding of, inhibitor induces structural changes at the active site of the enzyme. A, loop region between residues 304 and 309 moves in toward the bound, saccharide, the resulting maximal mainchain movement being 5 A for His305., The side chain of residue Asp300 rotates upon inhibitor binding and makes, strong van der Waals contacts with the imidazole ring of His299. Four, histidine residues (His101, His201, His299, and His305) are found to be, hydrogen-bonded with the inhibitor. Many protein-inhibitor hydrogen bond, interactions are observed in the complex structure, as is clear, hydrophobic stacking of aromatic residues with the inhibitor surface. The, chloride activator ion and structural calcium ion are hydrogen-bonded via, their ligands and water molecules to the catalytic residues.
<StructureSection load='1b2y' size='340' side='right'caption='[[1b2y]], [[Resolution|resolution]] 3.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1b2y]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1B2Y OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1B2Y 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]] 3.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=AC1:6-METHYL-5-(4,5,6-TRIHYDROXY-3-HYDROXYMETHYL-CYCLOHEX-2-ENYLAMINO)-TETRAHYDRO-PYRAN-2,3,4-TRIOL'>AC1</scene>, <scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=G6D:6-DEOXY-ALPHA-D-GLUCOSE'>G6D</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</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=1b2y FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1b2y OCA], [https://pdbe.org/1b2y PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1b2y RCSB], [https://www.ebi.ac.uk/pdbsum/1b2y PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1b2y ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AMYP_HUMAN AMYP_HUMAN]
== 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/b2/1b2y_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=1b2y ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Crystal structures of human pancreatic alpha-amylase (HPA) in complex with naturally occurring inhibitors have been solved. The tetrasaccharide acarbose and a pseudo-pentasaccharide of the trestatin family produced identical continuous electron densities corresponding to a pentasaccharide species, spanning the -3 to +2 subsites of the enzyme, presumably resulting from transglycosylation. Binding of the acarviosine core linked to a glucose residue at subsites -1 to +2 appears to be a critical part of the interaction process between alpha-amylases and trestatin-derived inhibitors. Two crystal forms, obtained at different values of pH, for the complex of HPA with the protein inhibitor from Phaseolus vulgaris (alpha-amylase inhibitor) have been solved. The flexible loop typical of the mammalian alpha-amylases was shown to exist in two different conformations, suggesting that loop closure is pH-sensitive. Structural information is provided for the important inhibitor residue, Arg-74, which has not been observed previously in structural analyses.


==About this Structure==
Crystal structures of human pancreatic alpha-amylase in complex with carbohydrate and proteinaceous inhibitors.,Nahoum V, Roux G, Anton V, Rouge P, Puigserver A, Bischoff H, Henrissat B, Payan F Biochem J. 2000 Feb 15;346 Pt 1:201-8. PMID:10657258<ref>PMID:10657258</ref>
1B2Y is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with CL, CA and PCA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1B2Y OCA].


==Reference==
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
The active center of a mammalian alpha-amylase. Structure of the complex of a pancreatic alpha-amylase with a carbohydrate inhibitor refined to 2.2-A resolution., Qian M, Haser R, Buisson G, Duee E, Payan F, Biochemistry. 1994 May 24;33(20):6284-94. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8193143 8193143]
</div>
[[Category: Alpha-amylase]]
<div class="pdbe-citations 1b2y" style="background-color:#fffaf0;"></div>
 
==See Also==
*[[Amylase 3D structures|Amylase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Homo sapiens]]
[[Category: Single protein]]
[[Category: Large Structures]]
[[Category: Nahoum, V.]]
[[Category: Nahoum V]]
[[Category: Payan, F.]]
[[Category: Payan F]]
[[Category: CA]]
[[Category: CL]]
[[Category: PCA]]
[[Category: acarbose]]
[[Category: crystal structure]]
[[Category: human alpha-amylase]]
 
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 12 16:04:57 2007''

Latest revision as of 11:20, 6 November 2024

STRUCTURE OF HUMAN PANCREATIC ALPHA-AMYLASE IN COMPLEX WITH THE CARBOHYDRATE INHIBITOR ACARBOSESTRUCTURE OF HUMAN PANCREATIC ALPHA-AMYLASE IN COMPLEX WITH THE CARBOHYDRATE INHIBITOR ACARBOSE

Structural highlights

1b2y is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 3.2Å
Ligands:, , , , , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

AMYP_HUMAN

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Crystal structures of human pancreatic alpha-amylase (HPA) in complex with naturally occurring inhibitors have been solved. The tetrasaccharide acarbose and a pseudo-pentasaccharide of the trestatin family produced identical continuous electron densities corresponding to a pentasaccharide species, spanning the -3 to +2 subsites of the enzyme, presumably resulting from transglycosylation. Binding of the acarviosine core linked to a glucose residue at subsites -1 to +2 appears to be a critical part of the interaction process between alpha-amylases and trestatin-derived inhibitors. Two crystal forms, obtained at different values of pH, for the complex of HPA with the protein inhibitor from Phaseolus vulgaris (alpha-amylase inhibitor) have been solved. The flexible loop typical of the mammalian alpha-amylases was shown to exist in two different conformations, suggesting that loop closure is pH-sensitive. Structural information is provided for the important inhibitor residue, Arg-74, which has not been observed previously in structural analyses.

Crystal structures of human pancreatic alpha-amylase in complex with carbohydrate and proteinaceous inhibitors.,Nahoum V, Roux G, Anton V, Rouge P, Puigserver A, Bischoff H, Henrissat B, Payan F Biochem J. 2000 Feb 15;346 Pt 1:201-8. PMID:10657258[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. ↑ Nahoum V, Roux G, Anton V, Rouge P, Puigserver A, Bischoff H, Henrissat B, Payan F. Crystal structures of human pancreatic alpha-amylase in complex with carbohydrate and proteinaceous inhibitors. Biochem J. 2000 Feb 15;346 Pt 1:201-8. PMID:10657258

1b2y, resolution 3.20Å

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