1hay: Difference between revisions

Revision as of 18:39, 2 May 2008

SNAPSHOTS OF SERINE PROTEASE CATALYSIS: (B) ACYL-ENZYME INTERMEDIATE BETWEEN PORCINE PANCREATIC ELASTASE AND HUMAN BETA-CASOMORPHIN-7 JUMPED TO PH 10 FOR 10 SECONDS

OverviewOverview

Studies on the catalytic mechanism and inhibition of serine proteases are widely used as paradigms for teaching enzyme catalysis. Ground-breaking work on the structures of chymotrypsin and subtilisin led to the idea of a conserved catalytic triad formed by the active site Ser, His and Asp residues. An oxyanion hole, consisting of the peptide amide of the active site serine and a neighbouring glycine, was identified, and hydrogen bonding in the oxyanion hole was suggested to stabilize the two proposed tetrahedral intermediates on the catalytic pathway. Here we show electron density changes consistent with the formation of a tetrahedral intermediate during the hydrolysis of an acyl-enzyme complex formed between a natural heptapeptide and elastase. No electron density for an enzyme-product complex was observed. The structures also suggest a mechanism for the synchronization of hydrolysis and peptide release triggered by the conversion of the sp2 hybridized carbonyl carbon to an sp3 carbon in the tetrahedral intermediate. This affects the location of the peptide in the active site cleft, triggering the collapse of a hydrogen bonding network between the peptide and the beta-sheet of the active site.

About this StructureAbout this Structure

1HAY is a Single protein structure of sequence from Sus scrofa. Full crystallographic information is available from OCA.

ReferenceReference

X-ray snapshots of serine protease catalysis reveal a tetrahedral intermediate., Wilmouth RC, Edman K, Neutze R, Wright PA, Clifton IJ, Schneider TR, Schofield CJ, Hajdu J, Nat Struct Biol. 2001 Aug;8(8):689-94. PMID:11473259 Page seeded by OCA on Fri May 2 18:39:04 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
 [[Image:1hay.jpg|left|200px]]
- {{Structure
+<!--
-|PDB= 1hay |SIZE=350|CAPTION= <scene name='initialview01'>1hay</scene>, resolution 1.7&Aring;
+The line below this paragraph, containing "STRUCTURE_1hay", creates the "Structure Box" on the page.
-|SITE= <scene name='pdbsite=CAT:Active+Site+Catalytic+Triad'>CAT</scene>
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Pancreatic_elastase Pancreatic elastase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.36 3.4.21.36] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1hay|  PDB=1hay  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1hay FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1hay OCA], [http://www.ebi.ac.uk/pdbsum/1hay PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1hay RCSB]</span>
-}}
 '''SNAPSHOTS OF SERINE PROTEASE CATALYSIS: (B) ACYL-ENZYME INTERMEDIATE BETWEEN PORCINE PANCREATIC ELASTASE AND HUMAN BETA-CASOMORPHIN-7 JUMPED TO PH 10 FOR 10 SECONDS'''
@@ Line 34: / Line 31: @@
 [[Category: Wilmouth, R C.]]
 [[Category: Wright, P A.]]
-[[Category: hydrolase (serine proteinase)]]
+[[Category: Serine proteinase]]
-[[Category: serine proteinase]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 18:39:04 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:01:25 2008''