Sandbox Wabash3

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Kenton Hicks, Kyle Stucker, Allen Betts
Kenton Hicks, Kyle Stucker, Allen Betts
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Trypsin is serine protease which catalyzes the hydrolysis of peptide bonds of a substrate via an acylation reaction and a deacylation reaction. In the first (acylation) reaction, the nucleophilic serine attacks the substrate scissile bond, forming a tetrahedral intermediate and then a covalent acyl-enzyme with the release of the C-terminal fragment. In the second (deacylation) reaction, a water molecule attacks the acyl-enzyme, leading to a second tetrahedral intermediate followed by release of the N-terminal fragment. The specificity of substrates is determined by the structure of its specificity pocket, which contains Ser 195, His 57, and Asp 102. These three residues make up the <scene name='72/725340/Catalytic_triad/1'>catalytic triad</scene>, which are involved in catalyzing the reaction. An <scene name='72/725340/Oxyanion_hole/1'>oxyanion hole</scene> is specifically formed between the amide hydrogen atoms of Serine 195 and Glycine 193. This oxyanion hole stabilizes the tetrahedral intermediate through the distribution of negative charge to the cleaved amide.
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Trypsin is serine protease which catalyzes the hydrolysis of peptide bonds of a substrate via an acylation reaction and a deacylation reaction. In the first (acylation) reaction, the nucleophilic serine attacks the substrate scissile bond, forming a tetrahedral intermediate and then a covalent acyl-enzyme with the release of the C-terminal fragment. In the second (deacylation) reaction, a water molecule attacks the acyl-enzyme, leading to a second tetrahedral intermediate followed by release of the N-terminal fragment. Ser 195, His 57, and Asp 102. These three residues make up the <scene name='72/725340/Catalytic_triad/1'>catalytic triad</scene>, which is the active site of the enzyme that catalyzes the reaction. An <scene name='72/725340/Oxyanion_hole/1'>oxyanion hole</scene> is specifically formed between the amide hydrogen atoms of Serine 195 and Glycine 193. This oxyanion hole stabilizes the tetrahedral intermediate through the distribution of negative charge to the cleaved amide. The specificity of substrates is determined by the structure of its <scene name='72/725340/Specificity_pocket/2'>specificity pocket</scene>. The preference for lysine or arginine in trypsin catalysis is due to the composition of the trypsin specificity pocket. Asp 189 and one of two significant glycine backbones, Gly 216, interact with the ligand as they would with Arg or Lys.
== <ref>PMID:16636277</ref> ==
== <ref>PMID:16636277</ref> ==

Revision as of 18:36, 9 March 2016

Mechanism of Trypsin

Fumarase

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References

  1. Radisky ES, Lee JM, Lu CJ, Koshland DE Jr. Insights into the serine protease mechanism from atomic resolution structures of trypsin reaction intermediates. Proc Natl Acad Sci U S A. 2006 May 2;103(18):6835-40. Epub 2006 Apr 24. PMID:16636277
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