The outer parts of the mycobacterial envelope as permeability barriers

摘要: The permeability of mycobacteria to substances in their environment is controlled by the properties envelopes. Two special features are important: an outer lipid barrier based on a monolayer characteristic mycolic acids and capsule-like coat polysaccharide protein. mycolate layer prevents entry small hydrophilic molecules, which obtain access cell way pore-forming proteins resembling porins Gram-negative bacteria. More lipophilic molecules can diffuse through layer. capsule probably impedes macromolecules; intracellular pathogenic species it forms electron-transparent zone that separates bacterium from membrane host phagosome. structure seems common all mycobacteria, fast- slow-growing, but more abundant slow-growing species, group includes important mycobacterial pathogens. Mycobacteria secrete into environment, likely be pathogenesis diseases. Knowledge how these proteins, polysaccharides capsule, cross minimal at present. It proper knowledge will enable new approaches treatment disease.