Metabolic labelling of the carbohydrate core in bacterial peptidoglycan and its applications

Nat Commun. 2017 Apr 20:8:15015. doi: 10.1038/ncomms15015.

Abstract

Bacterial cells are surrounded by a polymer known as peptidoglycan (PG), which protects the cell from changes in osmotic pressure and small molecule insults. A component of this material, N-acetyl-muramic acid (NAM), serves as a core structural element for innate immune recognition of PG fragments. We report the synthesis of modifiable NAM carbohydrate derivatives and the installation of these building blocks into the backbone of Gram-positive and Gram-negative bacterial PG utilizing metabolic cell wall recycling and biosynthetic machineries. Whole cells are labelled via click chemistry and visualized using super-resolution microscopy, revealing higher resolution PG structural details and allowing the cell wall biosynthesis, as well as its destruction in immune cells, to be tracked. This study will assist in the future identification of mechanisms that the immune system uses to recognize bacteria, glean information about fundamental cell wall architecture and aid in the design of novel antibiotics.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacteria / classification
  • Bacteria / genetics
  • Bacteria / metabolism*
  • Carbohydrate Sequence
  • Cell Line
  • Cell Wall / chemistry
  • Cell Wall / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Escherichia coli / physiology
  • Gram-Negative Bacteria / genetics
  • Gram-Negative Bacteria / metabolism
  • Gram-Positive Bacteria / genetics
  • Gram-Positive Bacteria / metabolism
  • Macrophages / microbiology
  • Mice
  • Microscopy, Fluorescence
  • Molecular Structure
  • Muramic Acids / chemistry
  • Muramic Acids / metabolism*
  • Peptidoglycan / chemistry
  • Peptidoglycan / metabolism*
  • Time-Lapse Imaging

Substances

  • Muramic Acids
  • Peptidoglycan
  • N-acetylmuramic acid