Lipopolysaccharide: An indispensable source for potential targets and therapeutic design against Gram-negative bacteria

Gram-negative bacteria show more drug-resistant than Gram-positive bacteria due to unique structural attribute and cause significant morbidity and mortality across the globe. Such characteristic structure is an organelle lipopolysaccharide (LPS) on the outer membrane (OM) of cell wall essential for growth and survival of bacteria. LPS is a major cell wall component formed by dedicated transenvelope multiprotein complexes that shield the underlying peptidoglycan layer and play a key role in host–pathogen interactions with the innate immune system. Moreover, which constitutes the surface-exposed molecules with lipid portion in the outer leaflet of the OM that able to show antibiotic resistance and also responsible for the variety of biological effects associated with bacterial sepsis. LPS synthesis and structure are a conserved subject in infections during bacterial adaptive changes. Such changes ensue immune evasion, prolonged inflammation and augmented antibiotic resistance by working as molecular decoys which titrate the antimicrobials away from its intracellular antibiotic target. Herein, this review summarises the key features of LPS structure, function and biosynthesis. Moreover, it highlights the broad-spectrum conserved targets in the Raetz pathway without an alternative way for LPS biosynthesis vital for the development of novel therapeutic interventions against Gram-negative pathogens.