Difference Between Wall Teichoic Acid and Lipoteichoic Acid

The key difference between wall teichoic acid and lipoteichoic acid is that wall teichoic acids are covalently attached to peptidoglycan while lipoteichoic acids are anchored to the bacterial membrane via a glycolipid.

Teichoic acids are cell wall glycopolymers found in Gram-positive bacteria. They contain phosphodiester-linked polyol repeat units. They are mainly fibres of glycerol phosphate or ribitol phosphate. Teichoic acids fulfil several functions including the control of autolytic enzymes, regulation of divalent cations, attachment of surface proteins, or protection against antibacterial molecules, etc. Teichoic acids are highly negative charged polymers, and they are linked to carbohydrates via phosphodiester bonds. Wall teichoic acid and lipoteichoic acid are two cell wall teichoic acids found in Gram-positive bacteria. Wall teichoic acids are attached to peptidoglycan while lipoteichoic acids are anchored in the cytoplasmic membrane by a lipid anchor.

CONTENTS

1. Overview and Key Difference
2. What is a Wall Teichoic Acid 
3. What is a Lipoteichoic Acid
4. Similarities Between Wall Teichoic Acid and Lipoteichoic Acid
5. Side by Side Comparison – Wall Teichoic Acid vs Lipoteichoic Acid in Tabular Form
6. Summary

What is Wall Teichoic Acid?

Wall teichoic acid is a type of teichoic acid which is covalently attached to the peptidoglycan layer of Gram-positive bacteria. Structurally, wall teichoic acid polymer has two components: a disaccharide linkage unit and a main chain polymer composed of phosphodiester-linked polyol repeat units. They mainly anchor with N-acetylmuramic acid or a terminal D-alanine in the tetrapeptide cross-linkage between N-acetylmuramic acid units of the peptidoglycan layer. They are the most abundant PG-linked polymers found in many gram-positive organisms, especially in B. subtilis and S. aureus.

Wall teichoic acids are involved in many aspects of cell division in gram-positive bacteria. They are also essential for maintaining cell shape in rod-shaped bacteria. Moreover, they are required for beta-lactam resistance in Methicillin-resistant Staphylococcus aureus. Furthermore, wall teichoic acids mediate susceptibility to cationic antibiotics. In therapeutics, wall teichoic acids are possible targets to overcome resistant bacterial infections.

What is Lipoteichoic Acid?

Lipoteichoic acids are teichoic acids that are covalently anchored to the lipid in the cytoplasmic membrane. They are the second type of teichoic acids found in the gram-positive bacterial cell wall. Lipoteichoic acid is a major constituent of the cell wall.

A diacyl­glycerol moiety serves as a plasma membrane anchor for lipoteichoic acids. Structurally, lipoteichoic acid differs from the teichoic acid as it contains polyglycerol phosphates. Lipoteichoic acid is an acidic polymer that contributes a negative charge to the cell wall. These molecules act as receptor molecules for some Gram-positive bacteriophage.

What are the Similarities Between Wall Teichoic Acid and Lipoteichoic Acid?

• Both wall teichoic acids and lipoteichoic acid are two major constituents of the cell wall of gram-positive bacteria.
• Both are cell wall glycopolymers.
• They provide structural support to the cell wall of gram-positive bacteria.
• Moreover, they have long chains of ribitol or glycerol
• They are not found in gram-negative bacteria.

What is the Difference Between Wall Teichoic Acid and Lipoteichoic Acid?

Wall teichoic acids are a type of teichoic acids which are covalently attached to peptidoglycan while lipoteichoic acids are a type of teichoic acids which are anchored to the bacterial membrane via a glycolipid. So, this is the key difference between wall teichoic acid and lipoteichoic acid.

Below infographic tabulates the differences between wall teichoic acid and lipoteichoic acid.

Summary – Wall Teichoic Acid vs Lipoteichoic Acid

Teichoic acid is a cell wall glycopolymer found in gram-positive bacteria. They are important in maintaining the structure of the cell wall. There are two types of teichoic acids: wall teichoic acids and lipoteichoic acids. Wall teichoic acids are covalently attached to peptidoglycan. Lipoteichoic acids are covalently linked to lipid in the cell membrane. Wall teichoic acids are important for cell shape determination, regulation of cell division, pathogenesis, antibiotic resistance and other fundamental aspects of gram-positive bacterial physiology. Lipoteichoic acids are important in contributing negative charge to the cell wall. Moreover, they act as receptor molecules for some gram-positive bacteriophages. Thus, this summarizes the difference between wall teichoic acid and lipoteichoic acid.

Reference:

1. Brown, Stephanie, et al. “Wall Teichoic Acids of Gram-Positive Bacteria.” Annual Review of Microbiology, U.S. National Library of Medicine, 2013, Available here.
2. Tankeshwar, Acharya. “Teichoic Acid/Lipoteichoic Acid: Characteristics and Medical Importance.” Learn Microbiology Online, 26 Aug. 2019, Available here.

Image Courtesy:

1. “Structure of Teichoic acid from Micrococcaceae” By LHcheM – Own work (CC BY-SA 3.0) via Commons Wikimedia

2. “Lipoteichoic acid” By Michał Sobkowski – Own work, according to (1) and (2) (CC BY-SA 3.0) via Commons Wikimedia