Bacterial Lipopolysaccharide, OPS, and Lipid A
Lipopolysaccharides are amphiphilic molecules indispensable for viability and survival of Gram-negative bacteria, as they heavily contribute to the structural integrity of their outer membrane (OM) and to the protection of the bacterial cell envelope (Di Lorenzo et al. 2015). The highly ordered structure and low fluidity of the LPS layer, stabilized by electrostatic interactions between divalent cations (as Ca2+ and Mg2+) and negatively charged groups present on LPS molecules, are responsible for the increase of permeability to hydrophobic compounds and to higher molecular weight hydrophilic compounds but also for Gram-negative superior resistance to external stress factors. Indeed, only certain antibiotics directed against Gram-negative bacteria, such as polymyxin B, are able to destabilize abovementioned ionic interactions leading to the disruption of membrane integrity. In addition, since they are exposed toward the external environment, LPS molecules participate in crucial...
- Di Lorenzo F, Silipo A, Lanzetta R, Parrilli M, Molinaro A (2015) Bacterial lipopolysaccharides: an overview of their structure, biosynthesis and immunological activity. In: Cipolla L (ed) Carbohydrates chemistry: state-of-the art and challenges for drug development. Imperial College Press, London, pp 57–89Google Scholar