View source for 3gxn


==Crystal structure of apo alpha-galactosidase A at pH 4.5==
<StructureSection load='3gxn' size='340' side='right'caption='[[3gxn]], [[Resolution|resolution]] 3.01&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3gxn]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3GXN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3GXN FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[3gxp|3gxp]], [[3gxt|3gxt]]</div></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">GLA ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Alpha-galactosidase Alpha-galactosidase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.22 3.2.1.22] </span></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=3gxn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3gxn OCA], [https://pdbe.org/3gxn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3gxn RCSB], [https://www.ebi.ac.uk/pdbsum/3gxn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3gxn ProSAT]</span></td></tr>
</table>
== Disease ==
[[https://www.uniprot.org/uniprot/AGAL_HUMAN AGAL_HUMAN]] Defects in GLA are the cause of Fabry disease (FD) [MIM:[https://omim.org/entry/301500 301500]]. FD is a rare X-linked sphingolipidosis disease where glycolipid accumulates in many tissues. The disease consists of an inborn error of glycosphingolipid catabolism. FD patients show systemic accumulation of globotriaoslyceramide (Gb3) and related glycosphingolipids in the plasma and cellular lysosomes throughout the body. Clinical recognition in males results from characteristic skin lesions (angiokeratomas) over the lower trunk. Patients may show ocular deposits, febrile episodes, and burning pain in the extremities. Death results from renal failure, cardiac or cerebral complications of hypertension or other vascular disease. Heterozygous females may exhibit the disorder in an attenuated form, they are more likely to show corneal opacities.<ref>PMID:2152885</ref> <ref>PMID:1846223</ref> <ref>PMID:2171331</ref> <ref>PMID:2539398</ref> <ref>PMID:1315715</ref> <ref>PMID:7504405</ref> <ref>PMID:8395937</ref> <ref>PMID:8069316</ref> <ref>PMID:7531540</ref> <ref>PMID:7575533</ref> <ref>PMID:7759078</ref> <ref>PMID:7599642</ref> <ref>PMID:7596372</ref> <ref>PMID:8738659</ref> <ref>PMID:8875188</ref> <ref>PMID:8834244</ref> <ref>PMID:8931708</ref> <ref>PMID:8807334</ref> <ref>PMID:8863162</ref> <ref>PMID:9105656</ref> <ref>PMID:9100224</ref> <ref>PMID:9554750</ref> <ref>PMID:9452068</ref> <ref>PMID:9452090</ref> <ref>PMID:9452111</ref> <ref>PMID:10208848</ref> <ref>PMID:10090526</ref> <ref>PMID:10838196</ref> <ref>PMID:10666480</ref> <ref>PMID:11076046</ref> <ref>PMID:10916280</ref> <ref>PMID:11295840</ref> <ref>PMID:11668641</ref> <ref>PMID:11889412</ref> <ref>PMID:12694230</ref> <ref>PMID:12786754</ref> <ref>PMID:15162124</ref> <ref>PMID:15712228</ref> <ref>PMID:16533976</ref> <ref>PMID:19621417</ref>  
== 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/gx/3gxn_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=3gxn ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
Human lysosomal enzymes acid-beta-glucosidase (GCase) and acid-alpha-galactosidase (alpha-Gal A) hydrolyze the sphingolipids glucosyl- and globotriaosylceramide, respectively, and mutations in these enzymes lead to the lipid metabolism disorders Gaucher and Fabry disease, respectively. We have investigated the structure and stability of GCase and alpha-Gal A in a neutral-pH environment reflective of the endoplasmic reticulum and an acidic-pH environment reflective of the lysosome. These details are important for the development of pharmacological chaperone therapy for Gaucher and Fabry disease, in which small molecules bind mutant enzymes in the ER to enable the mutant enzyme to meet quality control requirements for lysosomal trafficking. We report crystal structures of apo GCase at pH 4.5, at pH 5.5, and in complex with the pharmacological chaperone isofagomine (IFG) at pH 7.5. We also present thermostability analysis of GCase at pH 7.4 and 5.2 using differential scanning calorimetry. We compare our results with analogous experiments using alpha-Gal A and the chaperone 1-deoxygalactonijirimycin (DGJ), including the first structure of alpha-Gal A with DGJ. Both GCase and alpha-Gal A are more stable at lysosomal pH with and without their respective iminosugars bound, and notably, the stability of the GCase-IFG complex is pH sensitive. We show that the conformations of the active site loops in GCase are sensitive to ligand binding but not pH, whereas analogous galactose- or DGJ-dependent conformational changes in alpha-Gal A are not seen. Thermodynamic parameters obtained from alpha-Gal A unfolding indicate two-state, van't Hoff unfolding in the absence of the iminosugar at neutral and lysosomal pH, and non-two-state unfolding in the presence of DGJ. Taken together, these results provide insight into how GCase and alpha-Gal A are thermodynamically stabilized by iminosugars and suggest strategies for the development of new pharmacological chaperones for lysosomal storage disorders.

Effects of pH and Iminosugar Pharmacological Chaperones on Lysosomal Glycosidase Structure and Stability.,Lieberman RL, D'aquino JA, Ringe D, Petsko GA Biochemistry. 2009 May 1. PMID:19374450<ref>PMID:19374450</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 3gxn" style="background-color:#fffaf0;"></div>

==See Also==
*[[Galactosidase 3D structures|Galactosidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Alpha-galactosidase]]
[[Category: Human]]
[[Category: Large Structures]]
[[Category: Lieberman, R L]]
[[Category: Disease mutation]]
[[Category: Disulfide bond]]
[[Category: Glycoprotein]]
[[Category: Glycosidase]]
[[Category: Hydrolase]]
[[Category: Lysosome]]
[[Category: Rna editing]]