1v1d: Difference between revisions
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==Nucleophilic and General Acid Catalysis at Physiological pH by a Designed Miniature Esterase== | |||
<StructureSection load='1v1d' size='340' side='right'caption='[[1v1d]]' scene=''> | |||
| | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1v1d]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1V1D OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1V1D FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr> | |||
| | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1v1d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1v1d OCA], [https://pdbe.org/1v1d PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1v1d RCSB], [https://www.ebi.ac.uk/pdbsum/1v1d PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1v1d ProSAT]</span></td></tr> | ||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/PAHO_BOVIN PAHO_BOVIN] Pancreatic hormone is synthesized in pancreatic islets of Langerhans and acts as a regulator of pancreatic and gastrointestinal functions. | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
== | Check<jmol> | ||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/v1/1v1d_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1v1d ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
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. | 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. | ||
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<ref>PMID:15280952</ref> | |||
Nucleophilic and general acid catalysis at physiological pH by a designed miniature esterase., Nicoll AJ, Allemann RK | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1v1d" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Bos taurus]] | |||
[[Category: Large Structures]] | |||
[[Category: Allemann RK]] | |||
[[Category: Nicoll A]] | |||
Latest revision as of 13:24, 9 May 2024
Nucleophilic and General Acid Catalysis at Physiological pH by a Designed Miniature Esterase
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