Sandbox Reserved 715: Difference between revisions
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The <scene name='Sandbox_Reserved_715/Zoom_on_active__site/1'>active site</scene> is located at the end of the cavity previously defined. This active site has a <scene name='Sandbox_Reserved_715/Zoom_on_pocket/1'>pocket topology</scene>. The three carboxylate groups of two aspartate (Asp17 and Asp138) and one glutamate (Gu190) engender a high negative charge at the active site. The Asp17 tallies with the catalytic nucleophile and the Glu190 is the general acide/base. The two regions, wich contain the catalytic amino acid residues, are highly conserved regions in GH32 family. | The <scene name='Sandbox_Reserved_715/Zoom_on_active__site/1'>active site</scene> is located at the end of the cavity previously defined. This active site has a <scene name='Sandbox_Reserved_715/Zoom_on_pocket/1'>pocket topology</scene>. The three carboxylate groups of two aspartate (Asp17 and Asp138) and one glutamate (Gu190) engender a high negative charge at the active site. The Asp17 tallies with the catalytic nucleophile and the Glu190 is the general acide/base. The two regions, wich contain the catalytic amino acid residues, are highly conserved regions in GH32 family. | ||
The crystal structure of the ''Thermotoga maritima'' β-fructosidase shows a glycerol molecule, which is in the substrate biding site mimicking the O4 and O6 hydroxyl-groups of the substrate fructose-unit. This structure also shows that the Asp138 forms hydrogen bonds to O3 and O4 of the fructose unit. The Ser75 forms also hydrogen bonds to the O4 hydroxyl of fructose and to the catalytic nucleophile Asp17<ref name="Molecular"> PMID:19535439 </ref>. | The crystal structure of the ''Thermotoga maritima'' β-fructosidase shows a glycerol molecule, which is in the substrate biding site mimicking the O4 and O6 hydroxyl-groups of the substrate fructose-unit. This structure also shows that the Asp138 forms hydrogen bonds to O3 and O4 of the fructose unit. The Ser75 forms also hydrogen bonds to the O4 hydroxyl of fructose and to the catalytic nucleophile Asp17<ref name="Molecular"> PMID:19535439 </ref>. | ||
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| '''Ser75''' : forms hydrogen bounds to the 04 hydroxyl of fructose unit || '''Glu190''' : general acide/base | | '''Ser75''' : forms hydrogen bounds to the 04 hydroxyl of fructose unit || '''Glu190''' : general acide/base | ||
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===The β-sandwich module=== | ===The β-sandwich module=== | ||
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==β-fructosidase applications== | ==β-fructosidase applications== | ||
β-fructosidase has many applications <ref>S.M. Kotwal, V. Shankar, Biotechnology Advances, Immobilized invertase, 2009</ref> because, as we said before, this enzyme hydrolyzes sucrose to release an equimolar mixture of fructose and glucose ( | β-fructosidase has many applications <ref>S.M. Kotwal, V. Shankar, Biotechnology Advances, Immobilized invertase, 2009</ref> because, as we said before, this enzyme hydrolyzes sucrose to release an equimolar mixture of fructose and glucose ("invert" sugar). This "invert" sugar syrup is very used in food industry because it provides a longer shelf life for products. For instance, invertase prevents cristallization in soft candies like cherry cordials. This enzyme is also used for artificial honey fabrication, pharmaceutical and papers industries, along with enzyme electrodes for the detection of sucrose. | ||
== External Ressources== | == External Ressources== | ||