9est: Difference between revisions

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STRUCTURAL STUDY OF PORCINE PANCREATIC ELASTASE COMPLEXED WITH 7-AMINO-3-(2-BROMOETHOXY)-4-CHLOROISOCOUMARIN AS A NONREACTIVATABLE DOUBLY COVALENT ENZYME-INHIBITOR COMPLEX

OverviewOverview

The complex of porcine pancreatic elastase (PPE) with 7-amino-3-(2-bromoethoxy)-4-chloroisocoumarin, a potent mechanism-based inhibitor, was crystallized and the crystal structure determined at 1.9-A resolution with a final R factor of 17.1%. The unbiased difference Fourier electron density map showed continuous density from O gamma of Ser 195 to the benzoyl carbonyl carbon atom and from N epsilon 2 of His 57 to the carbon atom at the 4-position of the isocoumarin ring in the inhibitor. This suggested unambiguously that the inhibitor was doubly covalently bound to the enzyme. It represents the first structural evidence for irreversible binding of an isocoumarin inhibitor to PPE through both Ser 195 and His 57 in the active site. The PPE-inhibitor complex is only partially activated in solution by hydroxylamine and confirms the existence of the doubly covalently bound complex along with the acyl enzyme. The benzoyl carbonyl oxygen atom of the inhibitor is not situated in the oxyanion hole formed by the amide (greater than NH) groups of Gly 193 and Ser 195. The complex is stabilized by the hydrogen-bonding interactions in the active site (from the N epsilon 2 of Gln 192 to the bromine atom in the inhibitor and the amino group at the 7-position of the isocoumarin ring to the carbonyl oxygen of Thr 41) and by van der Waals interactions. The inhibition rates of several 7-substituted 4-chloro-3-(bromoalkoxy)isocoumarins toward PPE were measured.(ABSTRACT TRUNCATED AT 250 WORDS)

About this StructureAbout this Structure

9EST is a Single protein structure of sequence from Sus scrofa with , and as ligands. Active as Pancreatic elastase, with EC number 3.4.21.36 Full crystallographic information is available from OCA.

ReferenceReference

Structural study of porcine pancreatic elastase complexed with 7-amino-3-(2-bromoethoxy)-4-chloroisocoumarin as a nonreactivatable doubly covalent enzyme-inhibitor complex., Vijayalakshmi J, Meyer EF Jr, Kam CM, Powers JC, Biochemistry. 1991 Feb 26;30(8):2175-83. PMID:1998677

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-[[Image:9est.gif|left|200px]]<br /><applet load="9est" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:9est.gif|left|200px]]<br /><applet load="9est" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="9est, resolution 1.9&Aring;" />
 '''STRUCTURAL STUDY OF PORCINE PANCREATIC ELASTASE COMPLEXED WITH 7-AMINO-3-(2-BROMOETHOXY)-4-CHLOROISOCOUMARIN AS A NONREACTIVATABLE DOUBLY COVALENT ENZYME-INHIBITOR COMPLEX'''<br />
 ==Overview==
-The complex of porcine pancreatic elastase (PPE) with, 7-amino-3-(2-bromoethoxy)-4-chloroisocoumarin, a potent mechanism-based, inhibitor, was crystallized and the crystal structure determined at 1.9-A, resolution with a final R factor of 17.1%. The unbiased difference Fourier, electron density map showed continuous density from O gamma of Ser 195 to, the benzoyl carbonyl carbon atom and from N epsilon 2 of His 57 to the, carbon atom at the 4-position of the isocoumarin ring in the inhibitor., This suggested unambiguously that the inhibitor was doubly covalently, bound to the enzyme. It represents the first structural evidence for, irreversible binding of an isocoumarin inhibitor to PPE through both Ser, 195 and His 57 in the active site. The PPE-inhibitor complex is only, partially activated in solution by hydroxylamine and confirms the, existence of the doubly covalently bound complex along with the acyl, enzyme. The benzoyl carbonyl oxygen atom of the inhibitor is not situated, in the oxyanion hole formed by the amide (greater than NH) groups of Gly, 193 and Ser 195. The complex is stabilized by the hydrogen-bonding, interactions in the active site (from the N epsilon 2 of Gln 192 to the, bromine atom in the inhibitor and the amino group at the 7-position of the, isocoumarin ring to the carbonyl oxygen of Thr 41) and by van der Waals, interactions. The inhibition rates of several 7-substituted, 4-chloro-3-(bromoalkoxy)isocoumarins toward PPE were measured.(ABSTRACT, TRUNCATED AT 250 WORDS)
+The complex of porcine pancreatic elastase (PPE) with 7-amino-3-(2-bromoethoxy)-4-chloroisocoumarin, a potent mechanism-based inhibitor, was crystallized and the crystal structure determined at 1.9-A resolution with a final R factor of 17.1%. The unbiased difference Fourier electron density map showed continuous density from O gamma of Ser 195 to the benzoyl carbonyl carbon atom and from N epsilon 2 of His 57 to the carbon atom at the 4-position of the isocoumarin ring in the inhibitor. This suggested unambiguously that the inhibitor was doubly covalently bound to the enzyme. It represents the first structural evidence for irreversible binding of an isocoumarin inhibitor to PPE through both Ser 195 and His 57 in the active site. The PPE-inhibitor complex is only partially activated in solution by hydroxylamine and confirms the existence of the doubly covalently bound complex along with the acyl enzyme. The benzoyl carbonyl oxygen atom of the inhibitor is not situated in the oxyanion hole formed by the amide (greater than NH) groups of Gly 193 and Ser 195. The complex is stabilized by the hydrogen-bonding interactions in the active site (from the N epsilon 2 of Gln 192 to the bromine atom in the inhibitor and the amino group at the 7-position of the isocoumarin ring to the carbonyl oxygen of Thr 41) and by van der Waals interactions. The inhibition rates of several 7-substituted 4-chloro-3-(bromoalkoxy)isocoumarins toward PPE were measured.(ABSTRACT TRUNCATED AT 250 WORDS)
 ==About this Structure==
-EST is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with SO4, CA and IBR as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=9EST OCA].
+EST is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=IBR:'>IBR</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9EST OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Single protein]]
 [[Category: Sus scrofa]]
-[[Category: Meyerjunior, E.F.]]
+[[Category: Meyerjunior, E F.]]
-[[Category: Powers, J.C.]]
+[[Category: Powers, J C.]]
 [[Category: Radhakrishnan, R.]]
 [[Category: CA]]
@@ Line 22: / Line 22: @@
 [[Category: hydrolase(serine proteinase)]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 13:02:33 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:18:29 2008''