Peptidoglycan cross-linking

**Peptidoglycan cross-linking** refers to the enzymatic process that forms covalent bonds between peptide side chains attached to N-acetylmuramic acid residues in adjacent glycan strands within the peptidoglycan layer of most bacteria. This process is catalyzed primarily by DD-transpeptidases—also known as penicillin-binding proteins—and sometimes by LD-transpeptidases. The resulting mesh-like structure provides essential mechanical strength and rigidity to the bacterial cell wall, enabling it to withstand high internal turgor pressure and maintain cellular shape[1][2][3][4][5]. The degree and pattern of cross-linking can vary among species and environmental conditions. Disruption or inhibition of this process—most notably by β-lactam antibiotics—compromises cell wall integrity, leading to osmotic lysis and death in susceptible bacteria[2]. Because it is a critical step in bacterial survival but absent from human cells, peptidoglycan cross-linking is a major therapeutic target for antibacterial drugs. **Note:** This entry describes a *biochemical process* rather than a discrete molecular entity such as an enzyme or receptor. While it is an essential antibiotic target pathway mediated by specific enzymes (transpeptidases), "Peptidoglycan cross-linking" itself does not refer to one protein or gene product; thus, its use as a canonical drug target name may be considered imprecise or incorrect for structured databases focused on individual molecules[2].

Other names

Peptidoglycan transpeptidationPeptidoglycan cross-linksCell wall cross-linking (bacterial)Murein cross-linking

Inhibition of transpeptidase enzymes responsible for peptidoglycan cross-linking, leading to weakened cell walls and bacterial lysis