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Penicillin-binding proteins of listeria monocytogenes--a re-evaluation
Dorota Korsak1, Joanna J Zawadzka, Maria E Siwińska
1Department of Bacterial Physiology, Institute of Microbiology, University of Warsaw, Poland,
Abstract:
Intact Listeria monocytogenes cells or membranes isolated from them were treated with [3H]penicillin to allow identification of the penicillin binding proteins (PBPs) located in the cytoplasmic membrane. In the former case the PBPs were released from the cells following disruption of the cell wall murein with Listeria monocytogenes bacteriophage lysin. The procedure described by Dougherty et al. (1996) for Escherichia coli, with some modifications, was used to evaluate the M(r)s of the individual PBPs and allowed direct quantitation of their copy number.
Insights
Researchers identified penicillin-binding proteins (PBPs) in Listeria monocytogenes using radiolabeled penicillin. This method quantifies PBPs in the cytoplasmic membrane after cell wall murein disruption.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Penicillin-binding proteins (PBPs) are essential targets for beta-lactam antibiotics.
- Understanding PBP localization and quantity is crucial for antibiotic development.
- Listeria monocytogenes is a significant foodborne pathogen requiring effective treatment strategies.
Purpose of the Study:
- To identify and characterize penicillin-binding proteins (PBPs) in the cytoplasmic membrane of Listeria monocytogenes.
- To develop a method for quantifying PBP copy numbers within the bacterial cell.
Main Methods:
- Treatment of intact Listeria monocytogenes cells and isolated membranes with [3H]penicillin.
- Disruption of the cell wall murein using Listeria monocytogenes bacteriophage lysin.
- Modified procedure based on Dougherty et al. (1996) for PBP molecular weight (M(r)) evaluation and quantitation.
Main Results:
- Successfully identified PBPs located in the cytoplasmic membrane of Listeria monocytogenes.
- Quantified the molecular weights (M(r)s) of individual PBPs.
- Determined the copy number of each PBP within the bacterial cell.
Conclusions:
- The study established a reliable method for identifying and quantifying PBPs in Listeria monocytogenes.
- This methodology provides insights into PBP expression levels, potentially aiding in the development of new antibiotics targeting this pathogen.