1mxo

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Revision as of 12:00, 21 February 2008

AmpC beta-lactamase in complex with an m.carboxyphenylglycylboronic acid bearing the cephalothin R1 side chain

Overview

beta-lactamases are the most widespread resistance mechanism to beta-lactam antibiotics, such as the penicillins and the cephalosporins. In an effort to combat these enzymes, a combination of stereoselective organic synthesis, enzymology, microbiology, and X-ray crystallography was used to design and evaluate new carboxyphenyl-glycylboronic acid transition-state analogue inhibitors of the class C beta-lactamase AmpC. The new compounds improve inhibition by over 2 orders of magnitude compared to analogous glycylboronic acids, with K(i) values as low as 1 nM. On the basis of the differential binding of different analogues, the introduced carboxylate alone contributes about 2.1 kcal/mol in affinity. This carboxylate corresponds to the ubiquitous C3(4)' carboxylate of beta-lactams, and this energy represents the first thermodynamic measurement of the importance of this group in molecular recognition by class C beta-lactamases. The structures of AmpC in complex with two of these inhibitors were determined by X-ray crystallography at 1.72 and 1.83 A resolution. These structures suggest a structural basis for the high affinity of the new compounds and provide templates for further design. The highest affinity inhibitor was 5 orders of magnitude more selective for AmpC than for characteristic serine proteases, such as chymotrypsin. This inhibitor reversed the resistance of clinical pathogens to the third generation cephalosporin ceftazidime; it may serve as a lead compound for drug discovery to combat bacterial resistance to beta-lactam antibiotics.

About this Structure

1MXO is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Beta-lactamase, with EC number 3.5.2.6 Full crystallographic information is available from OCA.

Reference

Nanomolar inhibitors of AmpC beta-lactamase., Morandi F, Caselli E, Morandi S, Focia PJ, Blazquez J, Shoichet BK, Prati F, J Am Chem Soc. 2003 Jan 22;125(3):685-95. PMID:12526668

Page seeded by OCA on Thu Feb 21 14:00:07 2008

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Retrieved from "http://52.214.119.220/wiki/index.php/1mxo"

@@ Line 1: / Line 1: @@
-[[Image:1mxo.jpg|left|200px]]<br /><applet load="1mxo" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1mxo.jpg|left|200px]]<br /><applet load="1mxo" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1mxo, resolution 1.83&Aring;" />
 '''AmpC beta-lactamase in complex with an m.carboxyphenylglycylboronic acid bearing the cephalothin R1 side chain'''<br />
 ==Overview==
-beta-lactamases are the most widespread resistance mechanism to, beta-lactam antibiotics, such as the penicillins and the cephalosporins., In an effort to combat these enzymes, a combination of stereoselective, organic synthesis, enzymology, microbiology, and X-ray crystallography was, used to design and evaluate new carboxyphenyl-glycylboronic acid, transition-state analogue inhibitors of the class C beta-lactamase AmpC., The new compounds improve inhibition by over 2 orders of magnitude, compared to analogous glycylboronic acids, with K(i) values as low as 1, nM. On the basis of the differential binding of different analogues, the, introduced carboxylate alone contributes about 2.1 kcal/mol in affinity., This carboxylate corresponds to the ubiquitous C3(4)' carboxylate of, beta-lactams, and this energy represents the first thermodynamic, measurement of the importance of this group in molecular recognition by, class C beta-lactamases. The structures of AmpC in complex with two of, these inhibitors were determined by X-ray crystallography at 1.72 and 1.83, A resolution. These structures suggest a structural basis for the high, affinity of the new compounds and provide templates for further design., The highest affinity inhibitor was 5 orders of magnitude more selective, for AmpC than for characteristic serine proteases, such as chymotrypsin., This inhibitor reversed the resistance of clinical pathogens to the third, generation cephalosporin ceftazidime; it may serve as a lead compound for, drug discovery to combat bacterial resistance to beta-lactam antibiotics.
+beta-lactamases are the most widespread resistance mechanism to beta-lactam antibiotics, such as the penicillins and the cephalosporins. In an effort to combat these enzymes, a combination of stereoselective organic synthesis, enzymology, microbiology, and X-ray crystallography was used to design and evaluate new carboxyphenyl-glycylboronic acid transition-state analogue inhibitors of the class C beta-lactamase AmpC. The new compounds improve inhibition by over 2 orders of magnitude compared to analogous glycylboronic acids, with K(i) values as low as 1 nM. On the basis of the differential binding of different analogues, the introduced carboxylate alone contributes about 2.1 kcal/mol in affinity. This carboxylate corresponds to the ubiquitous C3(4)' carboxylate of beta-lactams, and this energy represents the first thermodynamic measurement of the importance of this group in molecular recognition by class C beta-lactamases. The structures of AmpC in complex with two of these inhibitors were determined by X-ray crystallography at 1.72 and 1.83 A resolution. These structures suggest a structural basis for the high affinity of the new compounds and provide templates for further design. The highest affinity inhibitor was 5 orders of magnitude more selective for AmpC than for characteristic serine proteases, such as chymotrypsin. This inhibitor reversed the resistance of clinical pathogens to the third generation cephalosporin ceftazidime; it may serve as a lead compound for drug discovery to combat bacterial resistance to beta-lactam antibiotics.
 ==About this Structure==
-MXO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with PO4 and SM2 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Beta-lactamase Beta-lactamase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.2.6 3.5.2.6] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1MXO OCA].
+MXO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=SM2:'>SM2</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Beta-lactamase Beta-lactamase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.2.6 3.5.2.6] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MXO OCA].
 ==Reference==
@@ Line 16: / Line 16: @@
 [[Category: Blazquez, J.]]
 [[Category: Caselli, E.]]
-[[Category: Focia, P.J.]]
+[[Category: Focia, P J.]]
 [[Category: Morandi, F.]]
 [[Category: Morandi, S.]]
 [[Category: Prati, F.]]
-[[Category: Shoichet, B.K.]]
+[[Category: Shoichet, B K.]]
 [[Category: PO4]]
 [[Category: SM2]]
@@ Line 28: / Line 28: @@
 [[Category: serine hydrolase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 21:47:09 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:00:07 2008''

1mxo

From Proteopedia

Revision as of 12:00, 21 February 2008

Overview

About this Structure

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