From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
| Line 1: |
Line 1: |
| - | [[Image:1v1d.gif|left|200px]] | + | {{Seed}} |
| | + | [[Image:1v1d.png|left|200px]] |
| | | | |
| | <!-- | | <!-- |
| Line 9: |
Line 10: |
| | {{STRUCTURE_1v1d| PDB=1v1d | SCENE= }} | | {{STRUCTURE_1v1d| PDB=1v1d | SCENE= }} |
| | | | |
| - | '''NUCLEOPHILIC AND GENERAL ACID CATALYSIS AT PHYSIOLOGICAL PH BY A DESIGNED MINIATURE ESTERASE'''
| + | ===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.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_15280952}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 15280952 is the PubMed ID number. |
| | + | --> |
| | + | {{ABSTRACT_PUBMED_15280952}} |
| | | | |
| | ==About this Structure== | | ==About this Structure== |
| - | 1V1D is a [[Single protein]] structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1V1D OCA]. | + | 1V1D is a [[Single protein]] structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1V1D OCA]. |
| | | | |
| | ==Reference== | | ==Reference== |
| Line 26: |
Line 30: |
| | [[Category: Hormone]] | | [[Category: Hormone]] |
| | [[Category: Pancrea]] | | [[Category: Pancrea]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 11:57:58 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 00:33:12 2008'' |
Revision as of 21:33, 27 July 2008
Template:STRUCTURE 1v1d
NUCLEOPHILIC AND GENERAL ACID CATALYSIS AT PHYSIOLOGICAL PH BY A DESIGNED MINIATURE ESTERASE
Template:ABSTRACT PUBMED 15280952
About this Structure
1V1D is a Single protein structure. Full experimental 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
Page seeded by OCA on Mon Jul 28 00:33:12 2008
