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1v1d
From Proteopedia
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|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1v1d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1v1d OCA], [http://www.ebi.ac.uk/pdbsum/1v1d PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1v1d RCSB]</span> | ||
}} | }} | ||
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[[Category: pancrea]] | [[Category: pancrea]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:18:18 2008'' |
Revision as of 21:18, 30 March 2008
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
NUCLEOPHILIC AND GENERAL ACID CATALYSIS AT PHYSIOLOGICAL PH BY A DESIGNED MINIATURE ESTERASE
Overview
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 Structure
1V1D is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
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:15280952
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