New Insights into Lipidic Secondary Metabolites in Mycobacteria

Isamu      Matsunaga; Masahiko      Sugita

doi:10.2174/2212796811105010052

Abstract

Tuberculosis and some other mycobacterial infections remain a tremendous threat to mankind. Pathogenic mycobacteria are able to survive within the hosts even for years, and a chemical and biological basis for their adaptation mechanisms is now beginning to be unraveled. The lipid-rich cell wall of mycobacteria contains structurally diverse glycolipids that comprise the outermost layer and interact directly with the environments. Recent studies have revealed that production of these surface-exposed glycolipids is mediated by enzymes utilized typically for biosynthesis of secondary metabolites. As for defined secondary metabolites in plants, bacteria and fungi that are often produced in response to environmental stresses and play a critical role in protection from their enemies, production of these cell wall glycolipids is influenced significantly by external factors to which mycobacteria are exposed. Identification of lipidic secondary metabolites in mycobacteria and elucidation of their biosynthetic pathways and biological functions now provide a clue to how mycobacteria have evolved to survive and grow both in host tissues as well as in natural environments. Further, what is learned from these studies is of important medical implications, including the development of a novel type of vaccines and therapeutic agents against human mycobacterial infections.

Keywords: Mycobacteria, lipids, secondary metabolite, mycolic acid, polyketide synthase, non-ribosomal peptide synthetase, Secondary Metabolites, Gram-positive, aerobic bacilli, Mycobacterium, taxonomic genus, Mycobacteriaceae, hydrophobic cell, Mycobacterium tuberculosis, pathogensis, mycobacterial infection, galactose/arabinose polysaccharide, peptidoglycan, framework, mycolic acids, alkyl--hydroxy fatty acids, arabinose termini, sugar, Nocardia, Rhodococcus, Corynebacterium, carbon chains, primary metabolites, pH, density, fungi, Mycolate Derivatives, arabinogalactan-linked, ester-linked, alcohol group, Phthiocerol Derivatives, conjugated, Mannose Phosphomycoketide, anomer, isomers, Glycopeptidolipids, serotype-nonspecific, immune system, non-ribosomal peptide, acyl carrier protein, catalyzes, FAS system, enzymes, biological energy, eukaryotic type, mitochondria, chloroplasts, condensation processes, atypical, hydrophobic, Microbes, granuloma, Rhodococcus, chemotherapy, silica gel, peripheral blood, vaccines, biosurfactants, antibiotic agents