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Size Exclusion Chromatography to Analyze Bacterial Outer Membrane Vesicle Heterogeneity
Published on: March 31, 2021
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Modulation of bacterial outer membrane vesicle production by envelope structure and content
Carmen Schwechheimer1, Adam Kulp2, Meta J Kuehn3
1Department of Biochemistry, Duke University Medical Center, Durham, NC, 27710, USA. carmensch0311@gmail.com.
BMC Microbiology
|December 22, 2014
Summary
Gram-negative bacteria outer membrane vesicle (OMV) production is regulated by lipoprotein (Lpp) levels and periplasmic pressure. This study reveals distinct Lpp-dependent and independent pathways controlling OMV biogenesis.
Area of Science:
- Microbiology
- Cell Biology
- Biochemistry
Background:
- Outer membrane vesicles (OMVs) are crucial for Gram-negative bacterial functions like virulence and survival.
- OMVs also act as an envelope stress response mechanism.
- The regulation and mechanisms of OMV production remain largely unknown.
Purpose of the Study:
- To investigate the relationship between peptidoglycan (PG) crosslinking, lipoprotein (Lpp) levels, and OMV production.
- To explore the role of periplasmic pressure in modulating OMV biogenesis.
- To elucidate the function of NlpA in bacterial envelope architecture.
Main Methods:
- Analysis of Gram-negative bacterial mutants with altered PG remodeling and crosslinking.
- Characterization of OMV production under conditions of increased periplasmic pressure.
- Genetic analysis of nlpA deletion mutants in various envelope crosslinking backgrounds.
Main Results:
- Subtle PG modifications inversely correlate OMV production with bound Lpp levels.
- This inverse relationship is not observed when OMV production is driven by increased periplasmic pressure.
- NlpA plays a novel role in envelope architecture, particularly in strains lacking Lpp or OmpA crosslinks.
Conclusions:
- OMV production is regulated by both Lpp concentration-dependent and independent pathways.
- Periplasmic pressure represents an alternative driver of OMV biogenesis.
- NlpA is a significant factor in maintaining bacterial envelope integrity.
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