Reference : Kinetic and crystallographic studies of extended-spectrum GES-11, GES-12, and GES-14 ...
Scientific journals : Article
Life sciences : Biochemistry, biophysics & molecular biology
http://hdl.handle.net/2268/143574
Kinetic and crystallographic studies of extended-spectrum GES-11, GES-12, and GES-14 β-lactamases.
English
Delbrück, Heinrich [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH > > > >]
Bogaerts, Pierre [Université Catholique de Louvain - UCL > CHU Mont-Godinne > > >]
Kupper, Michaël [RWTH > > > >]
Rezende de Castro, Roberta [Université Catholique de Louvain - UCL > CHU Mont-Godinne > > >]
Bennik, Sandra [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH > > > >]
Glupczynski, Youri [Université Catholique de Louvain - UCL > CHU Mont-Godinne > > >]
Galleni, Moreno [Université de Liège - ULiège > Département des sciences de la vie > Macromolécules biologiques >]
Hoffmann, Kurt [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH > > > >]
Bebrone, Carine mailto [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH > > > >]
Nov-2012
Antimicrobial Agents and Chemotherapy
American Society for Microbiology (ASM)
56(11)
5618-5625
Yes (verified by ORBi)
International
0066-4804
1098-6596
Washington
DC
[en] GES-1 is a class A extended-spectrum β-lactamase conferring resistance to penicillins, narrow- and expanded-spectrum cephalosporins, and ceftazidime. However, GES-1 poorly hydrolyzes aztreonam and cephamycins and exhibits very low k(cat) values for carbapenems. Twenty-two GES variants have been discovered thus far, differing from each other by 1 to 3 amino acid substitutions that affect substrate specificity. GES-11 possesses a Gly243Ala substitution which seems to confer to this variant an increased activity against aztreonam and ceftazidime. GES-12 differs from GES-11 by a single Thr237Ala substitution, while GES-14 differs from GES-11 by the Gly170Ser mutation, which is known to confer increased carbapenemase activity. GES-11 and GES-12 were kinetically characterized and compared to GES-1 and GES-14. Purified GES-11 and GES-12 showed strong activities against most tested β-lactams, with the exception of temocillin, cefoxitin, and carbapenems. Both variants showed a significantly increased rate of hydrolysis of cefotaxime, ceftazidime, and aztreonam. On the other hand, GES-11 and GES-12 (and GES-14) variants all containing Ala243 exhibited increased susceptibility to classical inhibitors. The crystallographic structures of the GES-11 and GES-14 β-lactamases were solved. The overall structures of GES-11 and GES-14 are similar to that of GES-1. The Gly243Ala substitution caused only subtle local rearrangements, notably in the typical carbapenemase disulfide bond. The active sites of GES-14 and GES-11 are very similar, with the Gly170Ser substitution leading only to the formation of additional hydrogen bonds of the Ser residue with hydrolytic water and the Glu166 residue.
Alexander von Humboldt Foundation (Germany) - AvH
http://hdl.handle.net/2268/143574
10.1128/AAC.01272-12
We acknowledge the American Society for Microbiology

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