Related Experiment Video

Updated: Aug 10, 2026

Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria
12:57

Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria

Published on: September 16, 2013

Role of lipid A palmitoylation in bacterial pathogenesis

Russell E Bishop1, Sang-Hyun Kim, Ahmed El Zoeiby

  • 1Departments of Laboratory Medicine and Pathobiology, and Biochemistry, University of Toronto, Ontario, Canada. russell.bishop@utoronto.ca

Journal of Endotoxin Research
|June 14, 2005
PubMed

Insights

Regulated lipid A palmitoylation by the PagP enzyme helps bacteria evade host immunity and dampen immune responses. This mechanism varies among pathogens, influencing their survival strategies.

Area of Science:

  • Microbiology
  • Immunology
  • Biochemistry

Background:

  • Lipid A palmitoylation, the addition of a palmitate chain to lipid A, has been known but its functional significance in bacterial pathogenesis is recently understood.
  • The outer membrane enzyme PagP facilitates the incorporation of palmitate from phospholipids into lipid A.

Purpose of the Study:

  • To investigate the functional importance of regulated lipid A palmitoylation in bacterial pathogenesis.
  • To explore how PagP-mediated palmitoylation influences host-pathogen interactions and bacterial survival.

Main Methods:

  • Isolation and analysis of pagP mutants from pathogenic Gram-negative bacteria.
  • Studying the effects of palmitoylated lipid A on host immune defenses and TLR4 signaling.

Main Results:

  • Palmitoylated lipid A protects bacteria from host immune defenses.
  • Palmitoylated lipid A attenuates the activation of host immune responses via the TLR4 pathway.
  • Mechanisms of lipid A palmitoylation reflect the pathogenic lifestyle of different bacterial species.

Conclusions:

  • Regulated lipid A palmitoylation is a key bacterial virulence factor, modulating immune evasion and host immune activation.
  • The PagP enzyme and its substrate, palmitoylated lipid A, represent potential targets for anti-infective agents and tools for vaccine development.

More Related Videos

Enrichment of Bacterial Lipoproteins and Preparation of N-terminal Lipopeptides for Structural Determination by Mass Spectrometry10:59

Enrichment of Bacterial Lipoproteins and Preparation of N-terminal Lipopeptides for Structural Determination by Mass Spectrometry

Published on: May 21, 2018

Isolation of Lipoprotein Particles from Chicken Egg Yolk for the Study of Bacterial Pathogen Fatty Acid Incorporation into Membrane Phospholipids11:59

Isolation of Lipoprotein Particles from Chicken Egg Yolk for the Study of Bacterial Pathogen Fatty Acid Incorporation into Membrane Phospholipids

Published on: May 15, 2019

Related Concept Videos

Lipids as Anchors01:32

Lipids as Anchors

In the plasma membrane, the lipids forming the bilayer can also act as an anchor to tether proteins to the membrane. The three main types of lipid anchors found in eukaryotes are – prenyl groups, fatty acyl groups, and glycosylphosphatidylinositol or GPI groups. Prenyl and fatty acyl groups act as anchors on the cytosolic surface of the membrane, whereas GPI anchors proteins on the extracellular side.
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
Defense Against Bacterial Pathogens01:31

Defense Against Bacterial Pathogens

The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Biosynthesis of Lipids01:29

Biosynthesis of Lipids

Microbial membranes exhibit remarkable diversity in lipid composition, reflecting evolutionary adaptations to various environmental conditions. The three domains of life—Bacteria, Archaea, and Eukarya—synthesize membrane lipids through distinct biosynthetic pathways, leading to fundamental structural differences that impact membrane stability, function, and adaptability.Fatty Acid-Based Lipids in Bacteria and EukaryaBacteria and eukaryotes share a common fatty acid biosynthesis pathway, which...
Formation of Lipopolysaccharides01:19

Formation of Lipopolysaccharides

Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin, triggering...
Colonisation of Pathogens01:25

Colonisation of Pathogens

Pathogen colonization of host tissues is a critical step in the development of infectious diseases. Various pathogenic microorganisms, including bacteria, fungi, viruses, and protozoa, have evolved complex strategies to attach to, invade, and persist within host environments. These mechanisms enable pathogens to establish infections, evade immune responses, and resist antimicrobial treatments.Attachment to Host CellsIn bacteria, colonization typically begins with adherence to host epithelial...
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...