Molecular Classification
Enzyme, PLP-dependent amino acid racemase
Disease Roles
Infection

Alanine racemase Overview

Alanine racemase is an enzyme that catalyzes the reversible conversion of L-alanine to D-alanine. D-alanine is a critical component for the biosynthesis of peptidoglycan, which forms the structural framework of bacterial cell walls. The enzyme is found universally in prokaryotes but is absent from higher eukaryotes, making it an attractive target for antimicrobial drug development. It utilizes pyridoxal 5'-phosphate (PLP) as a cofactor. Inhibitors like D-cycloserine block peptidoglycan synthesis by preventing the production of D-alanine, leading to bacterial cell death. Because humans lack this enzyme entirely, selective inhibition offers high therapeutic potential with low host toxicity.

Mechanism of Action

Inhibition of alanine racemase, preventing D-alanine production necessary for peptidoglycan synthesis.

Biological Functions

Alanine and aspartate metabolism
D-alanine metabolism
Peptidoglycan biosynthesis

Disease Associations

Infection

Safety Considerations

  • Potential for resistance development in bacteria
  • Off-target effects of inhibitors (though minimized by absence of the enzyme in humans)

Interacting Drugs

D-cycloserine
3-Fluoro-D-alanine