Mycobacterial strains are known to survive environmental stresses and remain pathogenic to host cells. Elucidation of chemical structures constituting the mycobacterial cell wall has offered newer approaches to inhibit mycobaterial growth and motility. Molecular mimicry offers a promising approach to design chemical structures that affect the important survival component of mycobacteria, namely, the outer cell surface component. The presence of repeating units of arabino-, galactofuranosides, rhamno- and mannopyranosides, along with lipids, peptidolipids and inositolphosphates, prompts synthesis of glycolipids prepared from these sugar monomers. Synthetic oligosaccharide glycolipids mimic the cell surface components, such as, lipoarabinomannan. In a programme, a number of glycolipids constituted with arabinan and arabinomannan were synthesized, including oligosaccharides in the linear and branched fashion. In a series of studies involving M. smegmatis, the synthetic glycolipids were found to reduce the growth of the mycobacterium. Further, it was observed that the glycolipids affected the biofilm formation and sliding motilities of the mycobacteria. The varying extent of inhibitions could be correlated, to an extent, to the oligosaccharide structures and presence or absence of lipid portion. Further, the binding efficacies of synthetic glycolipids with surfactant protein A were also evaluated by surface plasmon resonance technique, from which a structure-affinity correlation could be derived in the form of kinetic on-off rates. Effects of synthetic glycolipids on mycobacterial growth, sliding motilities and biofilm formation will be presented.
References
“Synthesis, biological studies of linear and branched arabinofuranoside-containing glycolipids and their interaction with surfactant protein A”, Naresh, K.; Avaji, P. G.; Bharati, B. K.; Chatterji, D.; Jayaraman, N. Glycobiology, 2011, 21, 1237-1254.
“Synthesis of β-arabinofuranoside glycolipids, studies of their binding to surfactant protein-A and effect on sliding motilities of M. smegmatis”, Naresh, K.; Avaji, P. G.; Maiti, K.; Bharati, B. K.; Syal, K.; Chatterji, D.; Jayaraman, N. Glycoconjugate J., 2012, 29, 107-118.
