Diaminopimelic acid

Diaminopimelic acid

Diaminopimelic acid (often abbreviated DAP) is an amino acid that is a derivative of lysine. It is a key component in the synthesis of peptidoglycan, a major component of the cell wall in bacteria. DAP is not found in most eukaryotes, making it a target for antibiotic drugs.

Structure and Properties

Diaminopimelic acid is a diamino acid with three carbon atoms separating the two amino groups. It is a chiral molecule, with two possible enantiomers, D- and L-DAP. The L-enantiomer is the one most commonly found in nature.

Biological Role

In bacteria, DAP is incorporated into the peptidoglycan layer of the cell wall. It forms cross-links between the polysaccharide chains, providing strength and rigidity to the cell wall. This is crucial for the survival of the bacteria, as the cell wall protects the bacteria from changes in osmotic pressure and other environmental stresses.

Synthesis

DAP is synthesized from aspartic acid in a series of enzymatic reactions. The enzymes involved in this pathway are potential targets for antibiotic drugs, as they are not found in humans or other eukaryotes.

Clinical Significance

Because DAP is not found in eukaryotes, drugs that target its synthesis or incorporation into the cell wall can be selective for bacteria. This makes DAP a target for the development of new antibiotics. Several existing antibiotics, such as d-cycloserine, work by inhibiting the enzymes involved in DAP synthesis.

See Also

• Peptidoglycan
• Cell wall
• Antibiotics

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