Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Glycocalyx and its Functions

Glycocalyx and its Functions

The glycocalyx is a carbohydrate-rich, fuzzy-appearing layer on the outer surface of the cell membrane. It is highly hydrophilic, because of this it attracts large amounts of water to the cell's surface. This aids the cell's interaction with the watery environment and also helps it to obtain substances dissolved in the water. It is also important for cell identification, self/non-self determination, and embryonic development and is used in cell-to-cell attachments to form tissues.

Outer Layers of the Cell Envelope

Outer Layers of the Cell Envelope

The outermost layers of prokaryotic cells play a critical role in their survival, virulence, and interaction with the environment. These layers, often composed of polysaccharides, polypeptides, or proteins, form protective and adhesive structures that vary in organization and function.Capsules and Slime LayersCapsules are highly organized, tightly bound layers that firmly attach to the bacterial cell wall. Capsules are usually made of polysaccharides, though some are made of polypeptides. These...

Formation of Lipopolysaccharides

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,...

Peptidoglycan Synthesis

Peptidoglycan Synthesis

Structure of PeptidoglycanPeptidoglycan is a vital structural component of the bacterial cell wall, providing mechanical strength and shape to the cell. It consists of repeating units of two sugars—N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)—linked by β-1,4 glycosidic bonds. These sugar chains are cross-linked by short peptide chains, forming a mesh-like polymer that surrounds the bacterial plasma membrane.Cytoplasmic Phase – Precursor SynthesisPeptidoglycan...

Viral Structure

Viral Structure

Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.

Proteoglycans

Proteoglycans

Glycans, a class of complex heterogeneous molecules, can be covalently attached to proteins to form glycosylated proteins that regulate various physiological and pathological processes. Glycosylated proteins or glycoproteins comprise N-linked and O-linked oligosaccharides. O-glycosylation is the most common type of protein glycosylation. Here, glycans attach to the oxygen atom of the hydroxyl groups of Serine or Threonine residues. O-linked glycosylation occurs later in protein processing,...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Antarctic Fish Antimicrobial Peptides Active Against Bacterial and Viral Pathogens of Aquacultural Importance.

Antibiotics (Basel, Switzerland)·2026

Same author

Liposome formulation of a myristoylated antimicrobial peptide derived from Chionodracine: preparation, physico-chemical characterization and biological activity.

Colloids and surfaces. B, Biointerfaces·2026

Same author

Anticancer Activity of the Antimicrobial Myristoylated Peptide Myr-B in HeLa Cells: Cytotoxic, Membrane-Disruptive and Proteomic Insights.

International journal of molecular sciences·2026

Same author

Molecular and morphological signatures of drought and salinity stress in <i>Olea europaea</i>.

Frontiers in plant science·2026

Same author

An mRNA-based FimH nanoparticle vaccine against uropathogenic <i>Escherichia coli</i> is highly immunogenic in rodents.

Frontiers in immunology·2025

Same author

Temporal and Spatial Profiling of <i>Escherichia coli</i> O157:H7 Surface Proteome: Insights into Intestinal Colonisation Dynamics In Vivo.

Proteomes·2025

Search research articles

Related Experiment Video

Updated: Jul 29, 2025

Opsono-Adherence Assay to Evaluate Functional Antibodies in Vaccine Development Against Bacillus anthracis and Other Encapsulated Pathogens

Opsono-Adherence Assay to Evaluate Functional Antibodies in Vaccine Development Against Bacillus anthracis and Other Encapsulated Pathogens

Published on: May 19, 2020

Functional characterization of the gonococcal polyphosphate pseudo-capsule.

Benedetta Manca¹, Giada Buffi², Greta Magri²

¹Pharmacy and Biotechnology Department (FaBiT), University of Bologna, Bologna, Italy C/O GSK, Siena, Italy.

|May 22, 2023

Summary

Neisseria gonorrhoeae uses a polyphosphate (polyP) pseudo-capsule to evade immune defenses. This outer layer protects against serum killing, antimicrobial peptides, and phagocytosis, crucial for gonococcal pathogenesis.

More Related Videos

Automated Measurement of Cryptococcal Species Polysaccharide Capsule and Cell Body

Automated Measurement of Cryptococcal Species Polysaccharide Capsule and Cell Body

Published on: January 11, 2018

Homogeneous Glycoconjugate Produced by Combined Unnatural Amino Acid Incorporation and Click-Chemistry for Vaccine Purposes

Homogeneous Glycoconjugate Produced by Combined Unnatural Amino Acid Incorporation and Click-Chemistry for Vaccine Purposes

Published on: December 19, 2020

Related Experiment Videos

Last Updated: Jul 29, 2025

Opsono-Adherence Assay to Evaluate Functional Antibodies in Vaccine Development Against Bacillus anthracis and Other Encapsulated Pathogens

Opsono-Adherence Assay to Evaluate Functional Antibodies in Vaccine Development Against Bacillus anthracis and Other Encapsulated Pathogens

Published on: May 19, 2020

Automated Measurement of Cryptococcal Species Polysaccharide Capsule and Cell Body

Automated Measurement of Cryptococcal Species Polysaccharide Capsule and Cell Body

Published on: January 11, 2018

Homogeneous Glycoconjugate Produced by Combined Unnatural Amino Acid Incorporation and Click-Chemistry for Vaccine Purposes

Homogeneous Glycoconjugate Produced by Combined Unnatural Amino Acid Incorporation and Click-Chemistry for Vaccine Purposes

Published on: December 19, 2020

Area of Science:

Microbiology
Immunology
Bacterial Pathogenesis

Background:

Neisseria gonorrhoeae evades host immunity via multiple mechanisms.
Polyphosphate (polyP) accumulates on the gonococcal exterior, potentially forming a protective shield, but its role is debated.

Purpose of the Study:

To investigate the role of the polyP pseudo-capsule in Neisseria gonorrhoeae's immune evasion.
To determine if polyP contributes to resistance against serum bactericidal activity, antimicrobial peptides, and phagocytosis.

Main Methods:

Generated Neisseria gonorrhoeae mutants with altered polyP metabolism by deleting key enzymes.
Assessed the impact of polyP content on resistance to complement-mediated killing, cationic antimicrobial peptides (cathelicidin LL-37), and phagocytosis by neutrophil-like cells.
Utilized a recombinant polyP-binding protein to demonstrate the presence of the polyP pseudo-capsule.

Main Results:

Mutants with reduced surface polyP exhibited increased sensitivity to complement-mediated killing and cathelicidin LL-37.
Naturally serum-sensitive strains lacking a polyP pseudo-capsule gained resistance upon addition of exogenous polyP.
Strains lacking polyP showed decreased resistance to phagocytic killing, which was restored by exogenous polyP.

Conclusions:

The polyP pseudo-capsule is essential for Neisseria gonorrhoeae pathogenesis, providing protection against key host immune mechanisms.
Gonococci can exploit environmental polyP to enhance survival against complement, antimicrobial peptides, and intracellular killing.
These findings offer new insights into gonococcal biology and potential therapeutic strategies.