Effect of lactamase inhibitors on the biosensor penp during the measurement of lactam antibiotics concentration

Dagoberto Soto, Camila Silva, Cristian Ugalde, Kwok Yin Wong, Yun Chung Leung, Lok Yan So, Max Andresen

Research output: Journal article publicationJournal articleAcademic researchpeer-review


PenP is a fluorescent biosensor of lactam antibiotics (LA). It is structurally derived from the mutant lactamase TEM-1 comprising the substitution E166C, where fluorescein is covalently linked to cysteine. The presence of LA in the medium produces a change in the intrinsic fluorescence level of the biosensor, and the integral of the fluorescence level over time correlates directly with the LA concentration. Previously, we have successfully used PenP to determine the concentration of lactam antibiotics in clinical samples. The use of lactamase inhibitors (LI) is a common strategy to enhance the effect of LA due to the inhibition of an important resistance mechanism of pathogenic microorganisms. Structurally, LI and LA share the common element of recognition of lactamases (the lactam ring), but they differ in the reversibility of the mechanism of interaction with said enzyme. Because the biological recognition domain of PenP is derived from a lactamase, LI is expected to interfere with the PenP detection capabilities. Surprisingly, this work provides evidence that the effect of LI is marginal in the determination of LA concentration mediated by PenP.

Original languageEnglish
Article number1237
JournalSensors (Switzerland)
Issue number5
Publication statusPublished - 1 Mar 2019


  • Biosensor
  • Lactam antibiotics
  • Lactamase inhibitors
  • PenP
  • Use

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Atomic and Molecular Physics, and Optics
  • Instrumentation
  • Electrical and Electronic Engineering


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