Effects of Ser130Gly and Asp240Lys substitutions in extended-spectrum beta-lactamase CTX-M-9.
In CTX-M-9 extended-spectrum beta-lactamases (ESBLs), an S130G mutation induced a 40- to 650-fold increase in 50% inhibitory concentrations but decreased hydrolytic activity against cefotaxime. A D240K mutation did not modify enzymatic efficiency against ceftazidime. Residue K240 could interact with Q270 and therefore not with ceftazidime, in contrast with what was observed with certain TEM/SHV-type ESBLs.
Aumeran
C
C
Laboratoire de Bactériologie, Faculté de Médecine, 63001 Clermont-Ferrand, Cedex, France.
Chanal
C
C
Labia
R
R
Sirot
D
D
Sirot
J
J
Bonnet
R
R
D019943:Amino Acid Substitution; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002439:Cefotaxime / Q000378:metabolism; D002442:Ceftazidime / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D029968:Escherichia coli Proteins; D006868:Hydrolysis; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D009154:Mutation / Q000235:genetics / Q000502:physiology; D010957:Plasmids / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D029968:Escherichia coli Proteins; D002442:Ceftazidime; C412613:CTX-M-9 protein, E coli; D001618:beta-Lactamases; D002439:Cefotaxime