R164H and V240H replacements by site-directed mutagenesis of TEM-149 extended-spectrum β-lactamase: kinetic analysis of TEM-149H240 and TEM-149H164-H240 laboratory mutants

Antimicrob Agents Chemother. 2013 Feb;57(2):1047-9. doi: 10.1128/AAC.01268-12. Epub 2012 Nov 26.

Abstract

Two laboratory mutant forms, TEM-149(H240) and TEM-149(H164-H240), of the TEM-149 extended-spectrum β-lactamase enzyme were constructed by site-directed mutagenesis. TEM-149(H240) and TEM-149(H164-H240) were similar in kinetic behavior, except with respect to benzylpenicillin and ceftazidime. Molecular modeling of the two mutant enzymes demonstrated the role of histidine at position 240 in the reduction of the affinity of the enzyme for ceftazidime.

MeSH terms

  • Amino Acid Substitution
  • Anti-Bacterial Agents / metabolism*
  • Anti-Bacterial Agents / pharmacology
  • Biocatalysis
  • Ceftazidime / metabolism*
  • Ceftazidime / pharmacology
  • Drug Resistance, Multiple, Bacterial / genetics
  • Enterobacter aerogenes / drug effects
  • Enterobacter aerogenes / enzymology
  • Escherichia coli / drug effects
  • Kinetics
  • Microbial Sensitivity Tests
  • Mutagenesis, Site-Directed
  • Penicillin G / metabolism*
  • Penicillin G / pharmacology
  • Serratia marcescens / drug effects
  • Serratia marcescens / enzymology
  • beta-Lactamases / classification
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism*

Substances

  • Anti-Bacterial Agents
  • Ceftazidime
  • beta-Lactamases
  • Penicillin G