1v1d: Difference between revisions
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'''NUCLEOPHILIC AND GENERAL ACID CATALYSIS AT PHYSIOLOGICAL PH BY A DESIGNED MINIATURE ESTERASE''' | {{Structure | ||
|PDB= 1v1d |SIZE=350|CAPTION= <scene name='initialview01'>1v1d</scene> | |||
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|LIGAND= | |||
|ACTIVITY= | |||
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'''NUCLEOPHILIC AND GENERAL ACID CATALYSIS AT PHYSIOLOGICAL PH BY A DESIGNED MINIATURE ESTERASE''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1V1D is a [ | 1V1D is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1V1D OCA]. | ||
==Reference== | ==Reference== | ||
Nucleophilic and general acid catalysis at physiological pH by a designed miniature esterase., Nicoll AJ, Allemann RK, Org Biomol Chem. 2004 Aug 7;2(15):2175-80. Epub 2004 Jul 8. PMID:[http:// | Nucleophilic and general acid catalysis at physiological pH by a designed miniature esterase., Nicoll AJ, Allemann RK, Org Biomol Chem. 2004 Aug 7;2(15):2175-80. Epub 2004 Jul 8. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15280952 15280952] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Allemann, R K.]] | [[Category: Allemann, R K.]] | ||
[[Category: Nicoll, A.]] | [[Category: Nicoll, A.]] | ||
[[Category: cleavage on pair of basic | [[Category: cleavage on pair of basic residue]] | ||
[[Category: hormone]] | [[Category: hormone]] | ||
[[Category: | [[Category: pancrea]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 14:39:37 2008'' | ||
Revision as of 15:39, 20 March 2008
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NUCLEOPHILIC AND GENERAL ACID CATALYSIS AT PHYSIOLOGICAL PH BY A DESIGNED MINIATURE ESTERASE
OverviewOverview
A 31-residue peptide (Art-Est) was designed to catalyse the hydrolysis of p-nitrophenyl esters through histidine catalysis on the solvent exposed face of the alpha-helix of bovine pancreatic polypeptide. NMR spectroscopy indicated that Art-Est adopted a stable 3-dimensional structure in solution. Art-Est was an efficient catalyst with second order rate constants of up to 0.050 M(-1) s(-1). The activity of Art-Est was a consequence of the increased nucleophilicity of His-22, which had a reduced pK(a) value of 5.5 as a consequence of its interaction with His-18 and the positively charged Arg-25 and Arg-26. Mass spectrometry and NMR spectroscopy confirmed that the Art-Est catalysed hydrolysis of p-nitrophenyl esters proceeded through an acyl-enzyme intermediate. A solvent kinetic isotope effect of 1.8 indicated that the transition state preceding the acyl intermediate was stabilised through interaction with the protonated side-chain of His-18 and indicated a reaction mechanism similar to that generally observed for natural esterases. The involvement in the reaction of two histidine residues with different pK(a) values led to a bell-shaped dependence of the reaction rate on the pH of the solution. The catalytic behaviour of Art-Est indicated that designed miniature enzymes can act in a transparent mechanism based fashion with enzyme-like behaviour through the interplay of several amino acid residues.
About this StructureAbout this Structure
1V1D is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
ReferenceReference
Nucleophilic and general acid catalysis at physiological pH by a designed miniature esterase., Nicoll AJ, Allemann RK, Org Biomol Chem. 2004 Aug 7;2(15):2175-80. Epub 2004 Jul 8. PMID:15280952
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