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Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes
Published on: September 19, 2013
Murein-hydrolyzing activity of flagellin FlaA of Listeria monocytogenes
Magdalena Popowska1, Zdzislaw Markiewicz
1Department of Bacterial Physiology, Institute of Microbiology, Warsaw University Miecznikowa 1, 02-096 Warsaw, Poland. magdapop@biol.uw.edu.pl
Abstract:
In this preliminary report we show that a 29 kDa surface protein of Listeria monocytogenes EGD removed from cells with 4 M LiCl has peptidoglycan (murein) hydrolyzing activity, as revealed by zymographic analysis using Bacillus subtilis murein and heat-killed Micrococcus luteus cells casted in the gel. Following two-dimensional electrophoresis, the protein was electroblotted to PVDF membrane and its identity (FlaA) was revealed by sequencing. Peptidoglycan hydrolysing activity of FlaA purified by FPLC on Mono-S Sepharose against labelled Escherichia coli murein was demonstrated.
Insights
Researchers discovered a surface protein in Listeria monocytogenes, named FlaA, that possesses peptidoglycan hydrolyzing activity. This finding sheds light on bacterial cell wall degradation mechanisms.
Area of Science:
- Microbiology
- Bacterial Cell Wall Biology
- Protein Biochemistry
Background:
- Listeria monocytogenes is a significant foodborne pathogen.
- Bacterial surface proteins play crucial roles in cell wall interactions.
- Understanding peptidoglycan hydrolysis is key to bacterial physiology.
Purpose of the Study:
- To identify and characterize a peptidoglycan hydrolyzing protein from Listeria monocytogenes.
- To investigate the enzymatic activity of this surface protein.
Main Methods:
- Extraction of surface proteins using 4 M LiCl.
- Zymographic analysis with Bacillus subtilis murein and Micrococcus luteus.
- Two-dimensional electrophoresis and protein sequencing for identification.
- Purification using FPLC and activity assay with labeled Escherichia coli murein.
Main Results:
- A 29 kDa surface protein with peptidoglycan hydrolyzing activity was identified.
- The protein was identified as FlaA through sequencing.
- Purified FlaA demonstrated confirmed peptidoglycan hydrolyzing activity.
Conclusions:
- Listeria monocytogenes possesses a surface protein, FlaA, with murein hydrolyzing capabilities.
- FlaA is a potential target for understanding bacterial cell wall dynamics.
- This preliminary report establishes FlaA as an enzyme involved in peptidoglycan degradation.
